RU2777899C1 - Magnetic particles - Google Patents

Abstract

FIELD: testing.

SUBSTANCE: group of inventions relates to methods and systems for processing a sample for mixing, separating, filtering, or otherwise processing a sample (e.g., a liquid sample (fluid assay)) by using magnetic particles (e.g., ferrimagnetic particles) inducing movement under the effect of a magnetic node located at the periphery of the container containing the sample. Magnetic particle contains a magnetic material with a maximum field intensity in the range from 20 emu/g to 250 emu/g and a residual magnetisation in the range from 0 emu/g to 30 emu/g, wherein the magnetic particle has a diameter of at least 100 nm. The magnetic particle additionally contains a ligand-containing outer surface. Said ligand interacts with the analyte of interest in the sample solution.

EFFECT: improved mixing of ferrimagnetic particles in the sample, improved mass transfer, and reduction in the energy consumption.

17 cl, 5 dwg, 11 ex, 2 tbl

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under U.S. Provisional Application Serial No. 62/700658 entitled "MAGNETIC PARTICLES SUITABLE FOR MIXING IN RESPONSE TO A CHANGING MAGNETIC FIELD" filed July 19, 2018, the disclosure of which is incorporated herein by links in their entirety.

BACKGROUND OF THE INVENTION

[0002] Magnetic particles (for example, paramagnetic and superparamagnetic particles) are used for analysis and sample preparation in a wide variety of situations, including chemical and biological analyzes and diagnostics. Such paramagnetic and superparamagnetic particles have also been used in microfluidic systems. Magnetic particle technology is a robust technology that provides high performance (eg, device sensitivity and accuracy) as well as easy automation of assay protocols. In some applications, the surface of the magnetic particles may be coated with a suitable ligand or receptor (eg, antibodies, lectins, oligonucleotides, or other affinity groups) that can selectively bind the target substance or group of analytes in the mixture. In some applications, magnetic particles are used to mass transfer components from one substrate to another substrate. One of the key elements in the technology of separation and handling of magnetic particles is efficient mixing, which increases the rate of reaction between target substances and particle surfaces, mass transfer from one substrate to another, or transfer of an analyte from one medium to another.

[0003] Magnetic particles have also been used in sample plate applications. In magnetic sample plate systems, the sample plates comprise a plurality of constant field magnets positioned such that the magnets either protrude between the sample wells or position the sample wells in annular magnets. The magnetic particles in the sample wells can be agitated by placing a permanent magnet near the sample plate to ensure agitation. Other types of automatic stirrers typically attempt to achieve mixing by mechanical agitation (eg, by shaking the sample plate). After sample processing, magnets can be used to hold particles to the side of the sample wells to ensure liquid sample is removed. However, the constant field magnets used in common magnetic sample plate applications cannot provide reliable mixing. For example, magnetic particles typically tend to form aggregates and clusters in particular areas of sample wells. The magnetic particles move with the liquid through small turbulent regions using conventional agitation techniques, thus rendering the agitation inefficient. In addition, the plate itself must be moved between analysis steps, which requires significant automation.

SHORT DESCRIPTION

[0004] Accordingly, there is a need to improve the overall speed and efficiency of sample mixing and separation using magnetic particles, including ultra-fast uniform mixing of liquid samples. There is also a need for magnetic particles that have a fast response to external magnetic fields as well as low remanence. In addition, there is a need for the magnetic particles to remain suspended for a predetermined period of time after agitation. There is also a need for an agitation method that agitates the magnetic particles in the liquid rather than with the liquid.

[0005] Examples of the invention solve these and other problems, separately and together.

[0006] The first aspect relates to the magnetic particle. The magnetic particle contains a magnetic material having a maximum field strength in the range of about 20 emu/g to about 250 emu/g and a remanence in the range of about 0 emu/g to about 30 emu/g. The magnetic particle further comprises an outer surface containing a ligand. The ligand interacts with the analyte of interest in the sample solution.

[0007] Another aspect relates to the method of processing the sample. The method includes providing a magnetic particle with a ligand on the surface of the particle. The ligand selectively interacts with the analyte of interest in the sample. The magnetic particle has a maximum field strength in the range of about 20 emu/g to about 250 emu/g and a remanence in the range of about 0 emu/g to about 30 emu/g. The method further includes bringing the solution containing the analyte of interest into contact with the magnetic particle to cause the ligand to interact with the analyte of interest.

[0008] Another aspect relates to the method of processing the sample. First, a container containing ferrimagnetic particles and a sample is provided. The container is subjected to an alternating magnetic field, thereby moving the ferrimagnetic particles in the container and thereby processing the sample.

[0009] These and other examples are described in more detail below with reference to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1A-1D are views of various types of magnetism according to the present disclosure.

[0011] FIG. 2 is a block diagram of a sample handling system according to the present disclosure.

[0012] FIG. 3 is a graph of radians versus magnetic field energy density and shows how the magnetic field energy density varies between adjacent electromagnets according to the present disclosure.

[0013] FIG. 4A-4D are graphs showing DNA concentration for various aspects of Example 8 according to the present disclosure.

[0014] FIG. 5 shows High Performance Liquid Chromatography (HPLC) data for trypsin digestion of Example 9 according to the present disclosure.

DETAILED DESCRIPTION

[0015] The teachings of the present invention generally relate to methods and sample handling systems for mixing, separating, filtering, or otherwise treating a sample (e.g., a liquid sample (fluid sample)) by using magnetic particles (e.g., ferrimagnetic particles) that cause movement under the action of a magnetic assembly located on the periphery of the container containing the sample. While magnetic particles, such as ferrimagnetic particles, have been described in conjunction with numerous embodiments, aspects, and examples in accordance with the present disclosure, it is still contemplated that magnetic particles, such as ferromagnetic particles, paramagnetic particles, and superparamagnetic particles, or mixtures of various classes can also be used. magnetic particles. Thus, any specific reference to a ferrimagnetic particle can equally apply to a ferromagnetic particle, a paramagnetic particle, a superparamagnetic particle, or mixtures thereof.

[0016] The teachings of the present invention provide several technological advantages, including increased magnetic field strength within the sample volume, thereby allowing improved mixing, improved mass transfer, and/or reduced power consumption compared to prior art magnetic particle mixing systems. The ferrimagnetic particles can exhibit a strong magnetic susceptibility compared to conventional paramagnetic particles, thereby allowing more efficient mixing of the ferrimagnetic particles in the sample using a magnetic assembly that generates alternating magnetic fields. In addition, ferrimagnetic particles do not aggregate due to magnetic field-induced aggregation in the same way as ordinary ferromagnetic particles do.

[0017] Before discussing examples of this disclosure, some terms may be described in more detail.

[0018] As used herein, the term "ferrimagnetic particles" refers to particles containing ferrimagnetic material. Ferrimagnetic particles can respond to an external magnetic field (for example, an alternating magnetic field), but can demagnetize when the external magnetic field is removed. Thus, ferrimagnetic particles are efficiently mixed in the sample by external magnetic fields, and are also effectively separated from the sample using a magnet or electromagnet, but can remain suspended without the occurrence of magnetic field-induced aggregation.

[0019] The ferrimagnetic particles described herein are sufficiently receptive to magnetic fields so that they can move efficiently in a sample. In general, the field intensity range can be the same range as any electromagnet, provided that it is capable of moving particles. For example, the magnetic field has an intensity of about 10 mT to about 100 mT, about 20 mT to about 80 mT, and about 30 mT to about 50 mT. In some examples, more powerful electromagnets can be used to stir less receptive microparticles. In some examples, the magnetic field can be focused into the sample as much as possible. Also, electromagnets can be placed as close to the sample as possible, since the magnetic field strength decreases with the square of the distance.

[0020] In some examples, the ferrimagnetic particle contains ferrite. Ferrite includes a ceramic material that contains iron oxide combined with inorganic compounds containing metal, non-metal, or metalloid atoms. For example, the ferrite may comprise iron(III) oxide (Fe ₂ O ₃ ) mixed with one or more additional metal elements such as barium, manganese, nickel, zinc, titanium, or any other suitable metal element. Other examples of ferrites include Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ . Additional examples of ferrites include an iron core containing a sulfide or oxyhydroxide such as Fe ₇ S ₈ , Fe ₃ S ₄ , FeS or FeOOH.

[0021] Magnetite (Fe₃O_four) is another example of a ferrimagnetic material useful in the examples described herein, which is an example of a ferrite. Magnetite contains ions as Fe²⁺, and Fe³⁺. In some cases, the electron spins of Fe ions²⁺ and Fe³⁺ may be paired in the crystal structure such that magnetite is the ferrimagnet described herein. However, in some examples, the ferrimagnetic particles comprise any ferrimagnetic material (for example, ferrite). According to some examples, a ferrimagnetic material (for example, ferrite) may not be magnetite (Fe₃O_four), however, in some examples, magnetite is a suitable ferrimagnetic material.

[0022] Ferrites can be classified into two main families (hard magnetic ferrites and soft magnetic ferrites) based on their magnetic coercive force (eg, the ability of a material to withstand an external magnetic field without becoming demagnetized).

[0023] Hard magnetic ferrites have a high magnetic coercive force as well as a high remanence after magnetization. Hard magnetic ferrites can be used to make permanent magnets because hard ferrites do not easily demagnetize in the absence of an external magnetic field because they can have a high remanence. Examples of hard magnetic ferrites include strontium ferrite and barium ferrite.

[0024] Soft magnetic ferrites have a low magnetic coercive force. Soft magnetic ferrites also have low remanence after magnetization. The magnetization of soft magnetic ferrites is easier to change than hard magnetic ferrites. In addition, the magnetization of soft magnetic ferrites can easily change direction without dissipating large amounts of energy (eg, through hysteresis losses). Soft magnetic ferrites can also have a high electrical resistivity, thus preventing the formation of eddy currents in the material, which is another source of energy loss.

[0025] Soft magnetic ferrites may include manganese-zinc (MnZn) ferrite and nickel-zinc (NiZn) ferrite. Thus, in some examples, the ferrimagnetic particles contain MnZn ferrite. In other examples, the ferrimagnetic particles comprise NiZn ferrite. Ferrimagnetic particles containing MnZn ferrite and/or NiZn ferrite can become magnetized in the presence of an external magnetic field, and thus are able to move in the presence of an external magnetic field, but do not aggregate due to magnetic field-induced aggregation after removal of the external magnetic field, because they have low remanence.

[0026] Some ferrites can be considered as magnetically semi-hard ferrites. Magnetic semi-hard ferrites have properties that are between those of soft magnetic ferrites and those of hard magnetic ferrites. For example, cobalt ferrite (CoFe ₂ O ₄ ) is a semi-solid ferrite that can be magnetized in the presence of an external magnetic field (for example, an alternating magnetic field generated by a magnetic node), but does not have high remanence after the external magnetic field is removed, so that ferrimagnetic particles containing a cobalt ferrite core do not aggregate due to magnetic field-induced aggregation.

[0027] A "magnetic domain" is a region in a magnetic material in which the net magnetization is directed in one direction. Magnetic domains can arise in ferromagnetic and ferrimagnetic materials. The material may contain many magnetic domains. The magnetization in the magnetic domain can be oriented in a single direction. Each magnetic domain in a material can be oriented in a different direction. In the presence of an external magnetic field, the domains in the magnetic material can rotate so that the magnetization of each domain coincides with the external magnetic field.

[0028] The term "remanence" refers to the remanence that a material retains after the magnetic field is removed. Materials that have a high remanence after the magnetic field is removed retain a large magnetic field strength, while materials that have a low remanence after the magnetic field is removed have little or no magnetic field strength. Used in this document, the term "coated with a functional group surface" refers to a surface that is covered with fragments, each of which has a free functional group, which is associated with a ferrimagnetic particle; as a result, the surfaces of the ferrimagnetic particles are coated with functional group-containing fragments. The functional group acts as a bioaffinity absorbent for biological molecules in solution. In one example, the functional group is a carboxylic acid. A suitable free carboxylic acid moiety is a succinic acid moiety in which one of the carboxylic acid groups is bonded to the amino group of the aminosilanes via an amide bond and the second carboxylic acid group is unbound, resulting in a free carboxylic acid group attached or tethered to surface of a ferrimagnetic particle. Other suitable functional groups that can be used to coat the surface of ferrimagnetic particles include, but are not limited to, thiol groups, streptavidin, avidin, neutravidin, captavidin, amino groups, hydroxyl groups, tosyl groups, epoxy groups, alkyl groups, vinyl groups or aryl groups. According to additional examples, a biomolecule, such as an enzyme, protein, deoxyribonucleic acid (DNA), ribonucleic acid (RNA), immunoglobulin G, or an antibody (eg, a monoclonal antibody) can be coated on the surface.

[0029] The sample used in the present disclosure may be a liquid sample and may be, for example, a biological sample or a chemical sample. As used herein, the term "biological samples" may include biological fluids and may include, but is not limited to, blood, blood plasma, serum, or other bodily fluids or secretions such as, but not limited to, saliva, urine, cerebrospinal fluid , lacrimal fluid, sweat, gastrointestinal fluid, amniotic fluid, mucous fluid, pleural fluid, sebaceous fat, exhaled air, etc. Chemical samples may include any suitable types of samples containing chemicals to be detected, including water samples.

[0030] Appropriate biological samples may also include lysates prepared from cells derived from or from mammalian tissue, cell culture or bodily fluids, nucleic acid samples eluted from agarose or polyacrylamide gels, solutions containing multiple varieties of DNA molecules obtained either from amplification by polymerase chain reaction (PCR), or from the procedure for choosing the size of the DNA strand, and solutions obtained from the post-sequencing reaction. Suitable samples may be mixtures of biomolecules (e.g., proteins, polysaccharides, lipids, small molecule enzyme inhibitors, oligonucleotides, primers, templates) and other substances such as agarose, polyacrylamide, trace metals, and organic solvents from which the target nucleic acid molecule can be isolated. acids.

[0031] The term "analyte" refers to a substance, the presence, absence or concentration of which should be determined according to the examples of this disclosure. Examples of analytes may include, but are not limited to, biological molecules such as hormones (such as thyroid hormones, estradiol, testosterone, progesterone, estrogen), metabolites (such as glucose or ethanol), proteins, lipids, carbohydrates and sugars, steroids (such as vitamin D), peptides (such as procalcitonin), and nucleic acids. The analyte can also be cells, cell components (such as cell membranes), spores, biomarkers (pharmaceuticals such as antibiotics, benzodiazepines), drugs (such as immunosuppressants, narcotics, opioids, etc.), molecules with regulatory action in enzymatic processes such as promoters, activators, inhibitors or cofactors, microorganisms such as viruses (including EBV, HPV, HIV, HCV, HBV, influenza virus, norovirus, rotavirus, adenovirus, etc.), bacteria ( H. pylori , Streptococcus , MRSA, C. diff. , Ligionella , etc.), fungi, parasites (Plasmodium, etc.). Examples of this disclosure may also allow simultaneous analysis of multiple analytes of the same class or different classes (eg, simultaneous analysis of metabolites and proteins). In examples of this disclosure, analysis of a particular analyte, such as a biomarker, may indicate that a particular condition (eg, disease) is associated with a sample that contains the analyte.

[0032] As used herein, the term "isolated" is intended to mean that the material in question is in a physical environment other than that in which it occurs naturally and/or from which it was wholly or partially isolated. or purified from other non-target molecules.

[0033] As used herein, the terms "selective" and "selectively" refer to the ability to isolate specific species of biological molecules, such as a DNA molecule or molecules, based on a particular property, such as molecular size, from a combination that includes or is a mixture of species molecules such as host cell lysate and other components of the host cell. In some examples, selective isolation of particular molecular species is achieved by using an appropriate precipitating agent (e.g., a polyalkylene glycol salt) resulting in precipitation and facilitated adsorption of particular DNA species (e.g., characterized based on size) on the surfaces of the ferrimagnetic particles of this disclosure.

[0034] The term "analyzer" includes any suitable instrument that is capable of analyzing a sample, such as a biological sample. Examples of analyzers include mass spectrometers, immunoanalyzers, hematology analyzers, microbiological analyzers, and/or molecular biology analyzers.

I. MAGNETIC PARTICLES

[0035] According to various aspects of the ideas of the present invention, magnetic particles, such as ferrimagnetic particles, for example, can be mixed throughout the container. The ferrimagnetic particles are affected (eg, moved) by changing the magnetic field generated by the magnetic assembly.

[0036] The ferrimagnetic particles of the present disclosure have a high sensitivity to magnetic fields, so that the ferrimagnetic particles are easily mixed in the sample in the presence of an external alternating magnetic field. The ferrimagnetic particles may also have a low remanence so that the ferrimagnetic particles are not magnetically attracted to each other when the external alternating magnetic field is removed. As a result, the ferrimagnetic particles can remain suspended without the occurrence of magnetic field-induced aggregation after agitation, and thus do not inhibit binding or elution.

[0037] In addition, the ferrimagnetic particles must remain suspended in the sample for a suitable period of time after mixing. One skilled in the art will appreciate that a number of properties of the ferrimagnetic particles will affect this property. For example, the density as well as the remanence (eg, remanence) of the ferrimagnetic particles can affect the lifetime of the suspension in the sample after removal of the alternating magnetic field. In some instances, it is desirable to isolate the ferrimagnetic particles from the sample. In these examples, the ferrimagnetic particles can be magnetically separated from the container using a collection component such as a magnet or electromagnet as described herein.

[0038] Ferrimagnetic particles can have various shapes, which can be regular or irregular; in some examples, the shape maximizes the surface area of the particles. For example, the ferrimagnetic particles may be spherical, rod-shaped, elliptical, or any other suitable shape. Ferrimagnetic particles can have different densities, which can be determined from the composition of the core. In some examples, the density of the ferrimagnetic particles can be controlled using a coating, as described in this document.

[0039] In some examples, the ferrimagnetic particles have sufficient surface area to allow efficient binding of the target analyte, and are further characterized by the presence of surfaces that are capable of reversibly or irreversibly binding the target analyte (eg , biological molecules). In some examples, the surface area of the ferrimagnetic particles may range from about 0.1 m ² /g to about 500 m ² /g, from about 50 m ² /g to about 200 m ² /g, or from about 150 m ² /g up to approximately 175 m ² /g.

[0040] Suitable ferrimagnetic particles can be of such a size that their separation from solution is not difficult, for example, using magnetic methods or filtration. In addition, ferrimagnetic particles should not be too large so that their surface area is minimized, or so that they are not suitable for nanometer to micrometer scale manipulation.

[0041] Suitable sizes range from an average diameter of about 1 nm to an average diameter of about 1 mm, from about 5 nm to about 50 microns, or from about 100 nm to about 100 microns. A suitable size is from about 1 µm to about 10 µm. For example, in some examples, the ferrimagnetic particles may be nanoparticles (eg, particles with an average diameter less than 1 μm but greater than 1 nm). In other examples, the ferrimagnetic particles may be microparticles (eg, particles with an average diameter greater than 1 μm but less than 100 μm). In general, large ferrimagnetic particles (which are approximately 1 mm in size) are useful in cell fractionation, tissue digestion, fluid mixing, and the like.

[0042] The ferrimagnetic particles may be substantially solid or may have some degree of porosity. If the ferrimagnetic particles do include some degree of porosity, the pore size of individual pores may range from about 5 E to about 1000 E, from about 50 E to about 500 E. At least a plurality of pores may be through pores (e.g., extending entirely between opposite surfaces). The pore sizes or overall porosity of the ferrimagnetic particles can be determined according to a variety of suitable methods. For example, the total volume of an ideal (eg, non-porous) ferrimagnetic particle can be determined, and then the volume of the actual porous scaffold material can be determined. The porosity is then calculated by subtracting the volume of the actual porous framework material from the volume of the ideal ferrimagnetic particle. The porosity of the ferrimagnetic particle or the size of the individual pores can also be determined by optical measurement with a microscope and image processing to measure the individual pores.

[0043] The ferrimagnetic particles described herein may include several different materials. To the extent that mixtures of materials are present, the total content of magnetic materials in the ferrimagnetic particles may be at least 50 wt.% of the ferrimagnetic particle, at least 70 wt.% of the ferrimagnetic particle, or even 100 wt.% of the ferrimagnetic particle. The ferrimagnetic particles may include any of the materials described herein. The non-magnetic material constituting the remainder of the ferrimagnetic particles may include, for example, any of the coating materials described herein. The non-magnetic material can be used as a coating to encapsulate the magnetic portion of the ferrimagnetic particle, it can also be used as a functional component to interact with and bind the analyte of interest. The non-magnetic material may also act as a filler component.

A. Magnetism

[0044] Those skilled in the art will be familiar with a number of different types of magnetism, including paramagnetism, superparamagnetism, ferromagnetism, antiferromagnetism, and ferrimagnetism. FIG. 1 shows examples of different types of magnetism. Arrows in FIG. 1A-1D indicate the magnetic moments of particles, such as electrons, in various materials, however, it is understood that atoms and molecules can also create magnetic moments. Each arrow represents a magnetic force (arrow length) and an orientation of the magnetic moment (arrow orientation).

[0045] Paramagnetism occurs in the presence of unpaired electrons in a material. In FIG. 1A shows the magnetic moments in a paramagnetic material in the absence of an external magnetic field. The magnetic moments are not aligned and can orient themselves in arbitrary directions due to thermal motion. The material has zero net magnetization because the magnetic moments are oriented in arbitrary directions, thus canceling each other out. In the presence of an external magnetic field, the magnetic moments align parallel to the external magnetic field. The paramagnetic material then forms an induced magnetic field in the direction of the external magnetic field, causing a net attraction. Paramagnetic materials exhibit magnetism only in the presence of an external magnetic field. Paramagnetic materials may be weakly sensitive to a magnetic field. Examples of paramagnetic materials include aluminum, oxygen, titanium, and iron oxide (FeO).

[0046] Materials that are ferromagnetic can be magnetized by an external magnetic field, for example, the material's magnetic moments align in one direction, and remain magnetized after the external magnetic field is removed. In FIG. 1B shows a series of aligned magnetic moments in a ferromagnetic material in the absence of an external magnetic field. The ferromagnetic material can generate an induced magnetic field in the direction of aligned magnetic moments.

[0047] Ferromagnetism is a property not only of the chemical composition of a material, but also of the crystal structure and microstructure of the material. For example, there are ferromagnetic metal alloys that contain elements that are not ferromagnetic. A ferromagnetic material is highly sensitive to an external magnetic field and tends to retain a magnetic field after the external magnetic field is removed. Particles containing ferromagnetic material may be subject to magnetic field induced aggregation because they retain a magnetic field. Thus, after the magnetic stirrer stirs the ferromagnetic particles in the sample, the ferromagnetic particles may remain magnetized and stuck together. Examples of ferromagnetic materials include iron, nickel and cobalt.

[0048] A ferrimagnetic material may have multiple groups of atoms with opposite magnetic moments. In FIG. 1D shows the magnetic moments of two different groups of atoms that are back-aligned and unequal. The magnetic moments of one group can be stronger than the magnetic moments of another group, thus causing net magnetism. The crystal structure of the ferrimagnetic material contains magnetic sublattices with magnetic moments, the magnetic moments of the two sublattices being inversely aligned and unequal. Opposite magnetic moments are unequal and spontaneous magnetization remains. Ferrimagnetic materials can also have high electrical resistivity. When the external magnetic field is removed from the ferrimagnetic material, the ferrimagnetic material may remain magnetized or may become unmagnetized, depending on the specific ferrimagnetic material. An example of a ferrimagnetic material is ferrite.

[0049] FIG. 1C shows the magnetic moments in an antiferromagnetic material. In this case, the two different groups are back-aligned and equal. One group of magnetic moments is oriented in one direction, while the second group of magnetic moments is oriented in the opposite direction. The strength of these two groups of magnetic moments is equal, thus, in the presence of an external magnetic field, an antiferromagnetic particle will not create an induced magnetic field.

[0050] Superparamagnetism is a fifth type of magnetic behavior in which nanoparticles, eg, smaller than 50 nm, made from a ferromagnetic or ferrimagnetic material are small enough to contain a single magnetic domain. Superparamagnetic materials may exhibit similar behavior to paramagnets outside of a magnetic field, but may be more sensitive to a magnetic field than paramagnetic materials in the presence of an external magnetic field.

[0051] According to various examples, the magnetic field strength of the ferrimagnetic particles may be greater than or equal to about 20 emu/g, about 25 emu/g, about 30 emu/g, about 35 emu/g, about 40 emu/g, about 45 emu/g g, approximately 50 emu/g, approximately 75 emu/g, approximately 100 emu/g, approximately 150 emu/g, approximately 175 emu/g, approximately 200 emu/g, approximately 225 emu/g, approximately 250 emu/g, in the range from about 20 emu/g to about 250 emu/g, or from about 35 emu/g to about 100 emu/g. This value can be thought of as the particle's maximum field strength, which is a measure of the magnetic field strength generated by the particle when subjected to a magnetic field. In combination with the magnetic field strength of the ferrimagnetic particles, the permeability of the ferrimagnetic particle must be sufficient to produce an induced magnetic field greater than or equal to approximately 10 emu/g, 15 emu/g, 20 emu/g, approximately 25 emu/g, approximately 30 emu/g , approximately 35 emu/g, approximately 40 emu/g, approximately 45 emu/g, approximately 50 emu/g, approximately 75 emu/g, approximately 100 emu/g, approximately 150 emu/g, approximately 175 emu/g, approximately 200 emu/g, about 225 emu/g, about 250 emu/g, ranging from about 10 emu/g to about 250 emu/g or from about 35 emu/g to about 100 emu/g. The magnetic field to which the ferrimagnetic particles are exposed may be from about 700 oersteds to about 800 oersteds, from about 725 oersteds to about 775 oersteds, less than, equal to or greater than about 700 oersteds, 725, 750, 775 or about 800 oersteds.

[0052] According to various examples, the remanence of ferrimagnetic materials can range from about 0 emu/g to about 30 emu/g, from about 0 emu/g to about 10 emu/g, from about 1 emu/g to about 8 emu /g, from about 3 emu/g to about 5 emu/g, less than, equal to or greater than about 0 emu/g, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or approximately 30 emu/g.

[0053] The magnetic components of the particles can be magnetic nanoparticles, magnetic submicron particles, or magnetic micrometer particles. The ferrimagnetic particles described herein may have many different structures. For example, the ferrimagnetic particles can be magnetic nanoparticles embedded in a polymer or silica matrix, silica or polymer sheathed magnetic beads, magnetic nanoparticles or magnetic beads, functionalized organic ligands, uncoated magnetic nanoparticles or beads. In instances where the ferrimagnetic particles are core-shell particles, the shell may include a coating as described herein.

B. Coating

[0054] The ferrimagnetic particles of the present disclosure may comprise a ferrimagnetic core surrounded by a coating. In an example, ferrimagnetic particles are coated with one or more layers of non-magnetic material. The use of coated ferrimagnetic particles that do not contain exposed iron on their surfaces can eliminate the possibility of iron preventing some further manipulation of the sample. The coating may be, for example, a polymer layer or a layer based on silica.

[0055] Examples of polymer layers may include polyethylene, polystyrene, polymethyl methacrylate, polyvinyl alcohol, or any other suitable polymer. Examples of silica-based layers may include silica, borosilicate, soda lime, barium titanate, and other types of glass. The polymeric or silica-based layer may be designed to control the density of the ferrimagnetic particles. For example, the polymeric or silica-based layer can control the density of the ferrimagnetic particles to a level close to that of a sample, eg, an aqueous sample (eg, about 1 g/cm ³ ).

[0056] In other examples, other types of coating may include a metallic coating such as aluminum, gold, zinc oxide, or any of the other coatings mentioned herein, and the like. Additionally, any of the coatings described herein may contain an incorporated fluorescent or color dye.

[0057] The coating may also contain a ligand, such as a capture reagent or a functional group, including those mentioned herein, for selective or non-selective binding of target analytes. The functional group may be designed to adsorb biomolecules, such as nucleic acids, which can non-sequence-specifically and reversibly bind to the functional group on the coating of the ferrimagnetic particles. Polynucleotides can be DNA, RNA or polyamide nucleic acids (PNA). In the example, the functional group is a carboxyl group. Various coatings containing functional groups suitable for these purposes are described in US patent No. 5705628, US patent No. 5898071 and US patent No. 6534262, the ideas of which are thus incorporated by reference into the present application in their entirety. Any of the coatings described herein can be functionalized with surface modification chemicals as described herein, eg, carboxylic acid, streptavidin, amine, hydrazide, silanol, azide. And they can be further functionalized with biological molecules such as antibodies, enzymes, DNA or RNA fragments, catalysts, and the like.

[0058] In some examples, the coating may contain a capture reagent. The capture reagent may be designed to capture the analyte in the sample. The surface of the ferrimagnetic particles may be coated with a capture reagent, which is a suitable ligand or receptor (e.g., antibodies, lectins, oligonucleotides, other affinity groups, or any of the other capture reagents mentioned herein) that can selectively bind the target analyte or group of analytes in mixtures. In some examples, the capture reagent may be an antibody.

[0059] Those skilled in the art will appreciate that any number of capture reagents can be used for this purpose, such as aptamers, nanoparticles, binding proteins, and the like. The capture reagent can be designed to capture a particular analyte or a particular panel of analytes, such as a drug detection panel or an endocrine function panel, and the like.

[0060] Alternatively, the ligand may include an enzyme. In some embodiments, the implementation of the enzyme may be associated with a coating for selective interaction with the substrate of this enzyme. When interacting with a substrate, an enzyme can function by destroying or degrading the substrate. This may result in the formation of the substance of interest by the action of the enzyme, or in the removal of the substrate from the sample. In various embodiments, the enzyme may be trypsin.

[0061] While only one coating layer has been described, it is understood that some examples may include multiple coating layers. For example, some examples may include a base metal coating with a polymer coating or a functional group located thereon. In some examples, the coating layer may function to sufficiently retain the outer coating on the ferrimagnetic particle.

C. Manufacturing

[0062] Ferrimagnetic particles can be manufactured using any suitable method for manufacturing nanoscale-micrometer magnetic particles. By way of example, US Pat. No. 5,648,124 discloses a process for preparing magnetically sensitive microparticles and is hereby incorporated herein by reference in its entirety. Ferrimagnetic particles can be made using any suitable ferrimagnetic material described herein.

[0063] For example, a ferrimagnetic particle can be made by first adding ferrimagnetic nanoparticles to a chemical bath. The nanoparticles can be encapsulated in an inorganic silica matrix, thus obtaining a microparticle that contains a plurality of ferrimagnetic particles. Sonication can then be used to help obtain these particles in a monodispersed form. Although the silica matrix is mentioned above, it is also possible to encapsulate individual ferrimagnetic nanoparticles or microparticles in other inorganic or organic materials. For example, ferrimagnetic nanoparticles can be encapsulated in SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO ₂ or any suitable ceramic material. As a further example, ferrimagnetic nanoparticles can be encapsulated in an organic material such as polyacrylic acid (PAA), poly(methyl acrylate) (PMA), polystyrene (PS), divinylbenzene (DVB), polyvinylpyrrolidone (PVP), or polyvinyl alcohol (PVA).

[0064] In another example, a ferromagnetic material can be used to make ferrimagnetic particles. The magnetic properties can be changed by changing the structure of the ferromagnetic material. Hematite (Fe ₂ O ₃ ) is a naturally occurring ferromagnet when allowed to crystallize in its pure form. However, if impurities such as nickel and zinc are added, then nickel and zinc can take the place of some of the iron atoms in the crystal structure, thus converting the naturally occurring ferromagnetic material into a ferrimagnetic particle. Or in another example, ferromagnetic hematite can be ground to a size of less than 50 nm such that each particle contains a single magnetic domain. In this form, the particle may be a superparamagnetic particle. An exemplary ferrimagnetic particle may be made from 50-100 nm ferrimagnetic magnetite nanoparticles bonded together in a silica or polymer. These nanoparticles are too large to be superparamagnetic.

II. SYSTEM

[0065] The teachings of the present invention generally relate to methods and sample handling systems for mixing, separating, filtering, or otherwise treating a sample (e.g., a liquid sample) in a container by using the ferrimagnetic particles of this disclosure that are induced to move under the action of a magnetic assembly located around the container.

[0066] Thus, the sample processing system of this disclosure may include a container, ferrimagnetic particles, a magnetic assembly located on the periphery of the container, and a control component connected to the magnetic assembly. The magnetic assembly may comprise at least one magnetic structure, each magnetic structure comprising a plurality of electromagnets disposed around the periphery of the container. Each electromagnet is separately controlled by a control component to create the required magnetic field in the container, effective for influencing ferrimagnetic particles, for example, according to a sample processing method including various stages. In some examples, the magnetic assembly may comprise a plurality of magnetic structures. The magnetic structures may be arranged in horizontal or substantially horizontal layers. In other examples, the magnetic structures may be arranged in vertical or substantially vertical layers.

[0067] In still other examples, a magnetically permeable shorting plate or structure may be present below, above and/or between the magnetic systems. The permeable shorting plate greatly reduces power consumption by concentrating the magnetic field in one specific location instead of two.

[0068] In some examples, the sample handling system may also include a magnet or electromagnet capable of collecting ferrimagnetic particles in the container, thereby separating the ferrimagnetic particles from the sample in the container.

[0069] Those skilled in the art will appreciate that the container, magnet assembly, and control component may be configured in any suitable manner to create alternating magnetic fields (eg, oscillating magnetic fields, rotating magnetic fields) in the container. In PCT Application No. PCT/IB2016/057189 Arnold etc. (Arnold et al.), fluid handling electromagnetic assemblies suitable for use in the present invention have been disclosed and are hereby incorporated by reference herein in their entirety.

A. Container

[0070] The sample processing system may include a container containing the sample to be processed. The container may generally be any type of container capable of holding a sample (eg, a liquid sample), such as a sample well, vessel, liquid reservoir, or the like, enclosing a liquid-containing chamber therein. As shown in FIG. 2, the sample processing system 200 may include a container 220. An exemplary container 220 may extend from an open, upper end (open to the outside atmosphere) to a lower, closed end such that the sample in container 220 may be loaded into the open, upper end and/or removed. from it using one or more liquid loading/collecting devices (not shown). Those skilled in the art will appreciate that the container may include a removable lid that can be connected to the open, top end (e.g., Eppendorf tube) at various stages of processing, e.g., to prevent leakage, contamination, and/or evaporation. Exemplary liquid loading/collecting devices may include, but are not limited to, manual sample loading devices (eg, a pipette), multichannel pipetting devices, acoustic liquid dispensing devices, and/or an autosampler, all as non-limiting examples.

[0071] The sample processing systems described herein can be configured to process samples at the microscale or macroscale (including large volume formats). In general, the macro scale includes liquid volumes in the milliliter range, while the micro scale liquid processing volumes include liquid volumes in the sub-milliliter range, such as microliters, nanoliters, or picoliters. Large volume formats may include handling liquid volumes greater than 1 ml. For example, sample processing systems in accordance with various aspects of the teachings of the present invention may be capable of handling fluid volumes from about 10 μl to about 1 ml and even more, including, for example, about 1.5 ml, about 2 ml, about 5 ml, about 10 ml. or more. However, in view of the teachings of the present invention, it will be appreciated that sample handling systems can handle any processable volume of liquid as described herein. In another example, the container may be capable of handling a volume of liquid from about 10 µl to 500 µl.

[0072] In accordance with various aspects of the teachings of the present invention, the systems and methods described herein can utilize containers that can be filled or partially filled with different volumes of sample, thereby reducing or increasing the volume of sample to be processed, depending on, for example, , the availability or cost of the sample, and/or the requirements of a particular assay. In some aspects, the samples to be processed (and the reagents used to process them) can be directly added to an open container (for example, by means of an autosampler or a pipette inserted into the open end of the container) and can likewise be directly removed from it (for example, by component to collect), for example, after processing.

[0073] As another example, the container may include a continuous fluid flow chamber. In some aspects, for example, the container may comprise an open port probe, wherein the open port probe comprises a tubular member, a sample inlet and a sample outlet, and an end open to the atmosphere and configured such that the sample inflow and outflow pointed towards the end to maintain a constant sample level. In related aspects, an open port probe may be configured to receive a substrate containing an analyte on at least a portion of its surface onto a sample to cause transfer of at least a portion of the analyte from the surface of the substrate to the sample. As a non-limiting example, the substrate may be a solid phase microextraction (SPME) fiber.

[0074] As an additional example, an open port probe may comprise an open tip tube that is configured to both insert and withdraw the sample in a continuous manner, providing a constant level of sample at the end. In this particular example, the open port probe may comprise a first cylindrical element positioned within a second cylindrical element placed in a coaxial configuration. The sample moves towards the end along the annular space between two cylindrical elements and then moves from the end along the inner cylinder. It should be appreciated that if there is no inflow or outflow of fluid, the sample level will remain constant and in many respects the open port probe will operate similarly to other containers previously described, such as a vessel. An open hole probe can be used to extract analytes from the surface of a substrate that comes into contact with the sample at the end. In several examples, ferrimagnetic particles can be introduced into the sample at the end of the open hole probe, and in combination with the sample handling systems and magnetic blocks and/or systems containing electromagnets described herein, the ferrimagnetic particles can be manipulated to resist sample outflow from end and remained near the end by means of the presence of magnetic fields. In addition, magnetic assemblies and/or structures cause rotation or movement back and forth in the x-, y- and z-directions of ferrimagnetic particles, limited by the presence of magnetic fields. Although electromagnets can be chosen strong enough to prevent any release of ferrimagnetic particles from the tip surface, a downstream permanent magnet or electromagnet (not shown) can also be used to capture ferrimagnetic particles, thereby preventing any further analysis from contamination. .

[0075] Although cylindrical elements have been described above in connection with the description of the pipe, it should be understood that other shapes with various sectional shapes can also be used, including triangular, square, rectangular, or any other multi-sided shape. The magnetic assemblies and/or magnetic structures that contain the electromagnets may be placed outside the metal tube, or they may be part of the metal tube itself and directly integral with the metal at or near the tip.

B. Magnetic assembly

[0076] Although the systems, devices, and methods described herein can be used in conjunction with many other sample processing systems, an exemplary sample processing system 200 is shown schematically in FIG. 2. It should be understood that the sample processing system 200 is only one possible sample processing system for use in accordance with the examples of systems, devices, and methods described herein, and all sample processing systems and/or components thereof with other configurations and performance characteristics can be also be used according to the systems, devices and methods described in this document. As shown in FIG. 2, an exemplary sample processing system 200 includes a magnet assembly 205 including at least one magnetic structure 210. The magnetic structure 210 includes a plurality of electromagnets 210a-d. As discussed in more detail below, the magnet assembly 205 is configured to generate (create) an alternating magnetic field or magnetic force in the container 220 and may include at least one magnetic structure 210 that can be positioned relative to the container 220 so as to generate in it a magnetic field. In some examples, the magnet assembly 205 may be configured to generate a static magnetic field, thereby collecting ferrimagnetic particles. Each magnetic structure 210 may include a plurality of electromagnets 210a-d, with each of the plurality of electromagnets 210a-d comprising an electrically conductive coil disposed around a center line that extends in the direction of the central axis of the magnetic structure 210.

[0077] As noted above, each magnetic structure 210 of the magnet assembly 205 may include a plurality of electromagnets 210a-d. Although the four electromagnets 210a-d refer to the magnetic structure 210, for example, it will be understood that the teachings of the present invention are not so limited, as any number of electromagnets capable of functioning in accordance with various aspects of Applicant's teachings may be used. For example, the magnetic structure 210 may include 2 electromagnets, 3 electromagnets, 4 electromagnets, 5 electromagnets, 6 electromagnets, 7 electromagnets, 8 electromagnets, 9 electromagnets, 10 electromagnets, or more. The electromagnets may include any electromagnet known to those skilled in the art, including, for example, a solenoid with a ferromagnetic core. The electromagnets may be of various shapes, including square, rectangular, round, elliptical, or any other shape capable of functioning according to various aspects of Applicant's ideas. In addition, in some aspects, magnetic lenses can be used to modify (eg, reshape) the magnetic field generated by the electromagnets in the container.

[0078] According to various aspects of the teachings of the present invention, the magnetic structure 210 may be included in various sample handling systems 200 and fluid handling devices. The sample handling system may include, for example, one or more magnetic structures 210 arranged in horizontal or substantially horizontal layers. Additionally or alternatively, in some examples, electromagnets of various magnetic designs 210 (e.g., from various vertically spaced layers) can be selectively energized to process different sample volumes and/or influence the characteristics of the magnetic field generated by magnetic assembly 205.

[0079] For example, the magnet assembly 205 may include a variety of magnetic structures. Each of the magnetic structures comprises a horizontal or substantially horizontal layer of electromagnets located in a plane perpendicular or substantially perpendicular to the vertical axis of container 220. As indicated by the number of magnetic structures, exemplary magnet assembly 205 may comprise a number of vertically spaced layers of magnetic structures, including 2 magnetic structures, 3 magnetic structures, 4 magnetic structures, 5 magnetic structures, 10 magnetic structures, 20 magnetic structures or more. In addition, it will be appreciated that although four electromagnets 210a-d are depicted as being associated with each magnet system 210 in FIG. 2, the ideas of the present invention are not limited in this way, as long as any number of electromagnets capable of functioning according to various aspects of the applicant's ideas, as further described herein, can be used. In addition, the magnetic designs of each layer are not necessarily identical. For example, although the electromagnets of a layer in the magnetic structures may be positioned with their center line extending towards the container 220, in some aspects the electromagnets in another layer may have a different configuration. By way of example, layer electromagnets in magnetic structures may be oriented substantially orthogonally (or at another non-zero angle) with respect to a plane containing the center line of the electromagnets.

[0080] Magnetic structures can be formed from a plurality of electromagnets located around the container 220 at one or more different vertical heights, with each electromagnet individually controlled to generate the desired alternating magnetic field (e.g., oscillating magnetic field, rotating magnetic field) in the container 220, effective for influencing the ferrimagnetic particles located in it. Based on the selective application of electrical signals to a plurality of electromagnets surrounding container 220, the ferrimagnetic particles can be manipulated to cause rotation, torsion, horizontal side-to-side movement, and/or vertical up and down movement in a liquid sample by the combined influence of magnetic fields generated by various electromagnets. As an example, signals applied to electromagnets 210a-d of each magnetic structure 210 (eg, in a single horizontal layer) may be designed to generate alternating magnetic fields substantially in the x-y plane, while signals applied to electromagnets of other magnetic structures may result in alternating magnetic fields exhibiting a z-direction component or a vertical component. Thus, the combined effect of a plurality of electromagnets can provide a magnetic field in container 220 with different characteristics, such as different strengths and/or directions, to, as a non-limiting example, quickly and efficiently mix the sample and/or trap target analytes in the sample.

[0081] In some examples, the vertical position of one or more magnetic structures 210 may be adjustable, for example, to handle different sample volumes and/or to influence the characteristics of the magnetic field generated by the magnetic assembly 205. As an example, in some aspects, the magnetic structure 210 may be vertically adjustable in accordance with various aspects of applicant's ideas depending on, for example, the volume of the sample in the container 220. It will be understood, for example, that the position of the magnetic structure 210 relative to ferrimagnetic particles and/or other magnetic structures can affect the location, intensity, intensity, direction or other characteristics of the magnetic field generated by the magnetic assembly 205 in the container 220. Thus, the magnetic structure 210 can be moved to various heights for optimal handling of liquids of different volumes and/or to change the characteristics of the magnetic field generated in the container 220. Although yes As described above for moving one magnetic structure relative to another magnetic structure of the magnet assembly 205, it will be understood that any number of layers of magnetic structures 210 can be moved by a positioning element (not shown) that is configured to adjust the position of one or more electromagnets 210a-d or one or more magnetic structures 210 relative to each other and/or to adjust the position of the entire magnetic assembly 205 relative to the container 220. Non-limiting examples of positioning elements may include rotary actuators, linear actuators, servo motors, electric motors, or the like. In some examples, the volume of the sample in the container 220 can be measured using a measuring device (not shown), so that the positioning element can automatically adjust the position of one or more electromagnets 210a-d and/or magnetic structures 210 based on the measured volume of the sample in the container 220 and/ or requirements of the sample processing protocol. In some examples, the positioning element may be configured to adjust the position of one or more electromagnets 210a-d and/or magnetic structures 210 based on user input, manual input, sample processing protocol, and/or predetermined volume.

[0082] Each electromagnet in the magnet assembly can generate an alternating magnetic field when the electric current passing through the solenoid of each electromagnet is an alternating current. As current changes direction through the solenoid coil, the magnitude and/or direction of the resulting magnetic field may change. In some examples, each electromagnet 210a-d of the magnetic structure 210 may receive an alternating current that is out of phase by a predetermined amount compared to the alternating current received by the other electromagnets of the magnetic structure 210. Thus, each electromagnet may generate an alternating magnetic field. The application of each of the generated alternating magnetic fields in the container may provide a rotating magnetic field.

C. Control Component

[0083] According to various aspects of the applicant's ideas, the control component may be connected to the magnetic node to control the alternating magnetic field. The control component may be configured to selectively actuate the solenoids of the magnet assembly by applying one or more radio frequency (RF) signals, direct current (DC) signals, alternating current (AC) signals, or the like. As a non-limiting example, in some aspects the control component may be configured to control the magnetic field generated by each of the plurality of electromagnets by applying a square wave signal (current) to each of the plurality of electromagnets. For example, a square wave signal may exhibit a frequency ranging from about 0.5 Hz to about 300 Hz, or from about 200 Hz to about 300 Hz. Alternatively, in some aspects, the control component may be configured to control the magnetic field generated by each of the plurality of electromagnets with AC signals applied to the plurality of electromagnets exhibiting various phase delays relative to each other to influence the desired movement of the ferrimagnetic particles in sample. Each electromagnet can generate an alternating magnetic field. For example, an AC signal applied to an electromagnet may cause an oscillating magnetic field or a rotating magnetic field to be generated. The control component may be configured to control the intensity of the magnetic field.

[0084] In some examples, using the control component, the frequency can be adjusted relative to the sensitivity of the ferrimagnetic particle. For example, slow moving ferrimagnetic particles may require a lower frequency so that they have more time to travel to the magnet, while fast moving ferrimagnetic particles require a higher frequency so that they do not immediately travel to the walls of the container. The magnitude of the particle velocity may depend on several variables, such as the magnetic sensitivity of the core material, the percentage of magnetic material in the core, particle size, and fluid viscosity (among other variables). By way of example, ferrimagnetic particles ranging in size from about 1 µm to about 2 µm can be subjected to magnetic fields tuned to a frequency of about 200 Hz. In some examples, significantly higher frequencies can be used to cause the beads to vibrate rather than to shuffle around, which can be used to fragment DNA.

[0085] In some examples, the control component may be configured to control the magnetic field generated by each of the plurality of electromagnets by applying a square wave or sinusoidal waveform to each of the plurality of electromagnets. Both a square wave and a sinusoidal waveform can cause similar effects in ferromagnetic particles, however, different waveforms have different power consumption levels in the device. This may be useful in minimizing the heat generation and power consumption of the device.

[0086] The control component may be configured to cause the electromagnets to generate a magnetic field of a certain intensity. As described herein, the field intensity range can be the same range as any electromagnet, as long as it is capable of moving the particles. In one example, the magnetic field has an intensity of about 10 mT to about 100 mT, or about 20 mT to about 80 mT, or about 30 mT to about 50 mT. In some examples, more powerful electromagnets can be used to stir much less sensitive microparticles. However, due to the power consumption and the need to be installed next to small tubes and microtiter plates, more powerful electromagnets are not practical under certain circumstances. The field can be focused in the pattern as much as possible. Also, electromagnets can be placed as close to the sample as possible, since the magnetic field strength decreases with the square of the distance. In still other examples, the control component may be configured to generate a magnetic field of about 15 mT for highly sensitive ferrimagnetic particles to about 90 mT for a short time to shake the ferrimagnetic particles. The intensity of the magnetic field can be in the range from 25 mT to 40 mT.

[0087] An exemplary control component may be a class D amplifier that uses pulse width modulation to drive a voltage at 22 kHz to produce a 300 Hz sinusoidal current. In some examples, other suitable types of amplifiers capable of producing an appropriate current waveform may be used. A Class D amplifier can perform best and generate the least amount of acoustic noise when using sinusoidal currents rather than square wave and triangular wave currents.

[0088] In some examples, the control component may generate currents in the electromagnets such that the electromagnet has an intrinsic inductance of about 10 mH to about 50 mH. In other examples, the electromagnet may have a self-inductance of from about 2 mH to about 15 mH.

[0089] In some aspects, DC signals may be effective in isolating electromagnets (e.g., drawing ferrimagnetic particles to one side and/or vertical level of a container) so that, as a non-limiting example, a sample or portion of a sample can be removed from the container without removal of ferrimagnetic particles.

[0090] In some aspects, said at least one AC waveform applied to each of a plurality of electromagnets may exhibit a phase delay relative to signals from another plurality of electromagnets. For example, the phase delay can be 30° phase delay, 60° phase delay, 90° phase delay, 120° phase delay, 150° phase delay, 180° phase delay, 210° phase delay, 240° phase delay, 270° phase delay, 300° phase delay, 330° phase delay, 360° phase delay, and any value or range between any two of these values (including endpoints). In one aspect, for example, a control signal applied to four electromagnets in each magnetic structure (for example, in each horizontal layer) may comprise an AC signal exhibiting a ±90° shift relative to adjacent electromagnets in that layer, and/or a control signal , applied to four electromagnets in each magnetic structure, may contain an AC signal exhibiting a ±90° shift relative to its vertically adjacent electromagnet in another magnetic structure (eg, in another horizontal layer). In some examples, the alternating magnetic field generated by the magnetic assembly may be a rotating magnetic field. An alternating current signal applied to each of the plurality of electromagnets, having a phase delay, may cause a rotating magnetic field to be generated. In some examples, a rotating magnetic field may be a magnetic field that has moving polarities, in which its opposite poles rotate around a center point or axis. Those skilled in the art will appreciate that AC waveforms need not be centered around 0 A.

[0091] FIG. 3 shows an exemplary magnetic field energy density between adjacent electromagnets. The graph includes magnetic field energy density between 210a and 210c, 210c and 210d, 210d and 210b, and 210b and 210a. The x-axis of the graph shows radians, while the y-axis shows the energy density of the magnetic field in mT. An AC signal applied to each of the plurality of electromagnets by the control component described herein can create alternating magnetic fields. In this example, the energy density of the magnetic field between 210a and 210c could be 25 mT at 0 radians. The energy density of the magnetic field between these two electromagnets oscillates in a sinusoidal wave pattern as shown in FIG. 3. The energy density of the magnetic field can fluctuate between each of the adjacent electromagnets.

[0092] Referring again to FIG. 2, exemplary sample processing system 200 further includes a control component 230 operatively coupled to magnet assembly 205 and configured to control alternating magnetic fields (eg, oscillating magnetic fields, rotating magnetic fields) generated by a plurality of electromagnets 210a-d. In various aspects, control component 230 may be configured to control one or more power supplies (not shown) configured to provide an electrical signal to a plurality of electromagnets 210a-d.

[0093] In some examples, the control component 230 may operate to regulate the magnetic field generated by each of the electromagnets 210a-d by controlling the amplitude, frequency, and direction of the electric current passing through the solenoid of each of the electromagnets 210a-d. In some examples, the electrical signal may be in the form of radio frequency (RF) signals, direct current, alternating current (eg, square wave), or the like. Of course, it will be appreciated that this document is contemplating any type of electrical current capable of operating according to various aspects of Applicant's ideas to aid in mixing a liquid sample. As an example, a DC signal may additionally or alternatively be applied to one or more current electromagnets to attract magnetic particles to one or more sides of the container (and out of the liquid volume) so as to, as a non-limiting example, assist in transferring liquid from the container after mixing step and/or prevent the removal of magnetic particles.

[0094] In various aspects, each electromagnet 210a-d in magnetic structure 210 may be separately controlled and actuated by control component 230. For example, control component 230 may provide RF signals or AC electrical signals with different phases to each of one or more electromagnets such that one or more of the electromagnets generates a different magnetic field relative to the other electromagnets. The plurality of electromagnets 210a-d may be located at different locations relative to the container 220, such that the orientation of the magnetic field generated by each electromagnet may be different even when the same electrical signal is applied to them. For example, since the pairs of electromagnets may be located on opposite sides of the container, the magnetic field generated by the electrode in each pair may be oriented in the same direction.

[0095] Thus, the magnetic field generated by the magnetic assembly 205 in the container 220 can be quickly and efficiently controlled to control the movement of the ferrimagnetic particles in the sample. In some examples, electrical signals and their characteristics (eg, phase shifts, frequency, amplitude) can be applied to various electromagnets according to a sample processing protocol. In view of the teachings of the present invention, it will be understood that the magnetic assembly 205 can be used to manipulate the ferrimagnetic particles in a sample in a variety of processes, including, but not limited to, protein analyses, sample derivatization (e.g., steroid derivatization, sample derivatization for gas chromatography, etc.). etc.) and/or cleaning and desalting the sample. After this treatment, processed samples (eg, liquids (fluids)) can be supplied to various analytical equipment (not shown), such as a mass spectrometer (MS) or any other suitable analyzer described herein, for analysis.

[0096] In various aspects, the control component may be any type of device and/or electrical component capable of driving an electromagnet. For example, in some aspects, the control component may comprise or be connected to a logic device (not shown) and/or a storage device, such as a computing device, configured to execute an application configured to provide instructions for controlling the electromagnets of the magnetic system(s). systems) 145. In some examples, the application may provide commands based on operator input and/or feedback from the sample processing system 200. In some examples, the application may include and/or a storage device may be configured to store one or more sample processing protocols for execution by the control component.

[0097] In various related aspects, the sample processing system may include at least one storage device operatively associated with the controller, configured, for example, to store at least one sample processing protocol for execution by the controller. In some aspects, the system may be configured to process at least one liquid by mixing it. In some aspects, the system may be configured to process at least one fluid by performing fluid separation to capture at least one target analyte in at least one fluid.

[0098] In some examples, the control component may be configured to perform degaussing. Degaussing is the process of reducing and/or eliminating the residual magnetic field. The control component may be configured to perform moderate demagnetization to further reduce the amount of remanence in the ferrimagnetic particles.

D. Component to collect

[0099] In some examples, the collection component may be located around the periphery of the container. The collection component may be capable of collecting the ferrimagnetic particles in the container, thereby separating the ferrimagnetic particles from the sample.

[00100] The collection component may include a magnet. For example, the collection component may include a magnet containing a ferromagnetic material. In some examples, the collection component may be brought to the periphery of the container after the ferrimagnetic particles have been mixed in the sample.

[00101] In some examples, the collection component may be an electromagnet. The electromagnet may be operatively coupled to the control component, wherein the control component is capable of controlling the electromagnet. The electromagnet may receive a DC electrical signal from the control component, thereby generating a static magnetic field. Ferrimagnetic particles can be manipulated by moving a specific area in the container under the influence of an applied static magnetic field.

[00102] In other examples, the collection component may be a magnetic assembly. For example, one or more electromagnets of magnetic design may receive a DC electrical signal from a control component, thereby generating a static magnetic field. Ferrimagnetic particles can be manipulated by moving a specific area in the container under the influence of an applied static magnetic field.

E. Analyzer

[00103] The sample handling system may also include an analyzer. In some examples, the analyzer may be located adjacent to the magnetic assembly. In other examples, a parser may be operably linked to a container. Those skilled in the art will appreciate that any suitable analyzer may be used to analyze the analyte or sample. The analyzer may include any suitable instrument that is capable of analyzing a sample, such as a biological sample. Examples of analyzers include mass spectrometers, immunoanalyzers, hematology analyzers, microbiological analyzers, and/or molecular biology analyzers. PCT Application No. PCT/US2018/033927 discloses an inline sample processing system with multiple detection capability and is hereby incorporated by reference herein in its entirety.

[00104] In some examples, the analyzer may be an immunoassay analyzer used to detect a label (chemiluminescent, electrochemiluminescent, fluorescent, radioactive isotope, DNA, etc.) or which uses a labelless system. Other types of analyzers may include hematology analyzers, microbiology analyzers, chemistry analyzers, urine analyzers, biochemistry analyzers, and/or molecular biology analyzers. When analyzing a biological sample, one or more of these types of analyzers, in any suitable combination, can be used to analyze the biological sample.

[00105] A hematology analyzer can be used to perform a complete blood count, an erythrocyte sedimentation rate (ESR), and/or a blood coagulation test. In automatic cell counting devices, blood is drawn and cell populations are quantified, classified and described using both electrical and optical techniques.

[00106] A microbiological analyzer can operate as a diagnostic tool to determine the identity of a biological organism. In some examples, the microbiological analyzer can detect the infecting microorganism. Such analyzers can use biochemicals in many small sample microwells in centrifugal rotors that contain a variety of substrates or in multiwell plates, depending on the type of test being performed.

[00107] A molecular biology analyzer may be a device that can analyze a biological sample at its molecular level. An example of a molecular biology analyzer may include a nucleic acid analyzer, such as a DNA analyzer.

[00108] The chemistry analyzer can perform analyzes on clinical samples such as blood serum, blood plasma, urine, and cerebrospinal fluid, detecting the presence of disease-related analytes or drugs. The chemical composition analyzer may use photometry. In photometry, the sample is mixed with an appropriate reagent to allow a reaction to occur that results in a color change. The concentration of the analyte determines the saturation of the resulting color. The photometer emits light of the appropriate wavelength onto the sample and measures the amount of light absorbed, which directly correlates with the analyte concentration in the sample. Another analytical method used in a chemical composition analyzer is the use of ion selective electrodes (ISE) to measure ions such as Na ⁺ , K ⁺ , C1 ^- and Li ⁺ . The ISE is a sensor that determines the concentration of ions in a solution by measuring the current flowing through an ion selective membrane.

[00109] A "mass spectrometer" is an instrument that can measure the masses and relative concentrations of atoms and molecules. In one example of a mass spectrometer, a primary magnetic force is applied to a moving charged particle. In general, the instrument ionizes the sample and then deflects the ions in a magnetic field based on the mass-to-charge ratio of the ion. The mass spectrum can then be used to determine the elemental or isotopic composition of the sample, the masses of particles and molecules, and to explain the chemical structures of molecules such as peptides and other chemical compounds. Commercially available mass spectrometers can be classified based on how they perform mass sorting, including time of flight, quadrupole MS, ion traps (including 3D quadrupole, cylindrical ion traps, linear quadrupole ion traps, orbital traps), ion cyclotron resonance with Fourier transform (FTMS), etc. Alternatively, they can be classified based on ion source (laser desorption, matrix-assisted laser desorption, thermal ionization, plasma, spark source, etc.) or detectors (electron multipliers (such as Faraday cup and ion-photon detectors), inductive detectors etc.). In one example, the mass spectrometer may be a triple quadrupole mass spectrometer.

III. WAY

[00110] The sample processing method can be carried out using the ferrimagnetic particles of this disclosure. The methods of this disclosure include providing a container containing ferrimagnetic particles and a sample. The container is then subjected to an alternating magnetic field generated by a magnetic assembly. The sample is then processed by moving the ferrimagnetic particles in a container. In some examples, the alternating magnetic field may be a rotating magnetic field. In other examples, the alternating magnetic field may be an oscillating magnetic field.

[00111] In some examples, as the ferrimagnetic particles move in the container, the ferrimagnetic particles can bind to cells located in the sample. After the ferrimagnetic particles bind to the cells, the ferrimagnetic particles can continue to move due to the action of the alternating magnetic field generated by the magnetic assembly. Thus, the cell can move throughout the sample. In other examples, ferrimagnetic particles can be associated with cells to collect/concentrate cells, as described in this document. In still other examples, ferrimagnetic particles can bind to cell surface molecules to identify cells. Ferrimagnetic particles can also be used to draw bound surface molecules from the cell membrane. A similar process can be used to modify cells.

[00112] In other examples, ferrimagnetic particles can be used to puncture a cell membrane or cell wall to deliver particles or reagents into the cell or nucleus (physical permeabilization of cell membranes, not due to the action of reagents). In addition, ferrimagnetic particles can be used to physically separate living or dead cells or cell components. In addition, ferrimagnetic particles can be used to selectively destroy one type of cell relative to another. In some examples, ferrimagnetic particles can be used to separate large molecules, such as DNA/RNA, through collisions between ferrimagnetic particles and large molecules. In other examples, ferrimagnetic particles can be used to promote resuspension of lyophilized reagents or particles.

[00113] After exposing the container to an alternating magnetic field, the ferrimagnetic particles can be collected using the collection component described herein. After the ferrimagnetic particles have been collected by the collection component, the sample processing protocol may further include eluting at least a portion of the sample from the container. A portion of the sample may be eluted by any suitable method.

[00114] After eluting a portion of the sample, analysis can be performed. The analysis can be carried out using the analyzer described above. In other examples, ferrimagnetic particles can be used to speed up chemical reactions such as enzymatic cleavage reactions or protein binding. As the ferrimagnetic particles move due to the alternating magnetic field, the ferrimagnetic particles can cause additional motion in the container (for example, through collisions with other particles in the container), thus mixing the sample and causing the chemical reaction to accelerate.

[00115] In addition, in some examples, the sample may contain inorganic compounds or small objects. Ferrimagnetic particles can move in the container under the influence of an alternating magnetic field generated by the magnetic assembly. Ferrimagnetic particles can bond with inorganic compounds or small objects in the sample. Then you can carry out additional analysis, described in this document. In other examples, the sample handling system can be used with ferrimagnetic particles, which can be very sensitive to a magnetic field and which can be used to mix less sensitive or non-magnetic particles or reagents in the sample.

[00116] In some examples, the ferrimagnetic particles may be a ferrofluid with the magnetic properties described herein. The sample handling system can stir the ferrofluid in the sample using an alternating magnetic field.

[00117] Many types of particles can be in a container with different values of sensitivity to the magnetic field. For example, the container may contain two groups of ferrimagnetic particles, such as a first group of ferrimagnetic particles containing a ferrite core containing MnZn ferrite, and a second group of ferrimagnetic particles containing a ferrite core containing NiZn ferrite. Each group of ferrimagnetic particles can be used to selectively isolate multiple analytes from the same sample (eg isolate a very receptive DNA binding particle first and then a slowly receptive protein binding particle). In addition, each group of ferrimagnetic particles in the container can be used for any purpose described in this document.

[00118] In still other examples, ferrimagnetic particles can be placed in the continuous supply system described herein, providing continuous mixing of the reactants flowing through the mixing chamber.

IV. KIT

[00119] According to various aspects of the ideas of the present invention, the kit may contain ferrimagnetic particles and a container. The ferrimagnetic particles may be in a container. The kit may additionally contain reagents for the required analytical methods. The reagent can be any suitable reagent (e.g. , precipitating reagent, wash buffers, elution buffers, etc.) that can be used in sample processing or analysis, e.g., testing the sample for the presence of a particular analyte, such as a biological molecule. In other examples, the kit may further comprise any part of the sample handling system described herein.

V. EXAMPLES

Example 1 Preparation of Solid Phase Reversible Immobilization (SPRI) Beads for DNA Extraction

[00120] The sample processing system of the examples of this disclosure can be used to isolate a nucleic acid, such as DNA, from a sample. This method may include two main parts: a preparation phase and a procedure implementation phase.

[00121] The preparation phase began with SPRI binding buffer. The binding buffer solution for SPRI contained, for example, PEG (polyethylene glycol) and salt (NaCl). Carboxy-coated ferrimagnetic particles, prepared as described in Example 6, were resuspended in SPRI binding buffer. The concentration of ferrimagnetic particles was normalized to that of the standard AmpureXP binding buffer supplied as part of a product available under the trade designation AMPure XP ^TM available from Beckman Coulter, Bray, CA, USA.

[00122] After preparing the SPRI binding buffer, a fresh 80% ethanol solution was prepared. A DNA sample was prepared by combining a 20 µm aliquot of a 100 bp DNA length marker, available under catalog number N3231S from New England BioLabs, INC., Ipswich, MA, USA, with 580 µl of DI water to make a 30:1 dilution. Then the power level of the control component is set to 75% and the frequency to 200 Hz of the sine wave. Plates and tubes were kept capped as far as possible to reduce evaporative change.

[00123] After completion of the preparation phase, the implementation phase of the procedure began. In some examples, in parallel with the procedure described below, the same procedure was performed manually using standard AmpureXP binding buffer as a control. Some of the diluted DNA was kept as another control.

[00124] 50 µl of diluted DNA and 90 µl of a mixture of ferrimagnetic particles (eg, binding buffer solution for SPRI) was added to a 0.5 ml Eppendorf tube (eg, container) to selectively precipitate DNA in the sample. The sample handling system described herein was used to thoroughly mix the contents of the Eppendorf tube to allow the precipitated DNA to bind to the ferrimagnetic particles.

[00125] After mixing the sample and the ferrimagnetic particles, the sample was incubated for 5 minutes while maintaining the ferrimagnetic particles in a suspended state. A magnet (eg , the electromagnets described herein) is then used to isolate the ferrimagnetic particles from the solution until clear, allowing the supernatant to be removed.

[00126] Then 200 μl of ethanol was added to the container. The sample handling system was then used to thoroughly mix the contents of the container, separate ferrimagnetic particles, and remove any supernatant.

[00127] 50 μl of deionized (DI) water was added to the container to elute the DNA from the ferrimagnetic particles. The sample handling system was used to thoroughly mix the sample. The sample was then incubated for 2 minutes while maintaining the ferrimagnetic particles in a suspended state. The magnet was then used to separate until clear and transfer the eluent solution to a new plate. After transferring the post-elution solution to a new plate, the DNA concentration in the post-elution solution was measured using, for example, a NanoDrop or PicoGreen assay. The concentration of the initially diluted DNA was then compared with the concentration after manual elution with AmpureXP.

[00128] Various examples describing methods for preparing and recoating SPRI beads are provided below.

Example 2 Synthesis of a Magnetic Core: Synthesis of a Core from Magnetite (Fe ₃ O _four )

[00129] The magnetic core of the magnetic particle was prepared by mixing 2.16 g of FeCl ₃ .6H2O and 64 ml of ethylene glycol in a 200 ml beaker to obtain a light brown solution without solids. 5.76 g of sodium acetate and 1.6 g of polyethylene glycol (PEG 400) were added to the solution, which was then stirred for 30 minutes. The stirred solution was transferred to a 100 ml autoclave reactor and heated there to 180° C. for 36 hours. After 36 hours, heating was stopped and the autoclave was cooled to room temperature. The resulting magnetite core particles with an average size of about 100 nm were collected with a permanent magnet and then washed with water 5 times.

Example 3 Bead Encapsulation: Coating Silica on a Magnetic Core

[00130] An encapsulated magnetite core was prepared by dispersing 20 g of the 100 nm magnetite core of Example 2 in 800 ml of methanol in a 1 L beaker. The mixture was sonicated for 30 minutes to ensure a homogeneous suspension. 370 ml of 28% ammonium hydroxide was added to the suspension, which was then stirred for 30 minutes. After sonication, a liquid mixture containing 0.5 ml of tetraethylorthosilicate and 4.5 ml of methanol was added dropwise to the suspension with additional sonication over a period of 0.5 h. After sonication, the beaker was closed and the suspension was continuously stirred for 15 h. After mixing, the encapsulated beads were captured with a permanent magnet. The encapsulated beads were then washed 5 times with water. The beads were then dried in an oven at 80°C for 24 hours.

Example 4 Surface Functionalization: Carboxylation of a Silica Coated Magnetic Core

[00131] A carboxylated silica coated magnetic core was prepared by dispersing 4 g of silica coated magnetite core particles prepared according to Example 3, dispersed in 150 ml of toluene, in a 500 ml flask with stirring. 20 g of (3-triethoxysilyl)propylsuccinic anhydride was added to the flask with stirring. Then 0.2 g of imidazole was added with stirring to obtain a homogeneous suspension. The slurry was refluxed at approximately 114° C. with stirring for 15 hours. After refluxing, the slurry was cooled to room temperature and a permanent magnet was used to collect solids from the slurry. The solids were first washed with methanol once and then with water 5 times and transferred to a 500 ml flask. 150 ml of 0.1 M acetic acid in water was added to the flask with stirring to obtain a homogeneous suspension. The suspension was heated to 90° C. for 15 hours. The suspension was cooled to room temperature. A permanent magnet was used to collect solids from the slurry. The solids were washed with water 5 times and dried in an oven at 60°C for 15 hours.

Example 5 Bead Encapsulation: Polymer Coating on Magnetic Core

[00132] An encapsulated polymer-coated magnetic core was prepared by dispersing 4 g of a 100 nm magnetite core prepared according to Example 2 in 100 ml of water in a 500 ml flask with stirring. 10 ml of acrylic acid was added to the flask with stirring along with 1 g of K ₂ S ₂ O ₈ to obtain a homogeneous suspension. The suspension was heated to 80°C for 15 h with stirring. The suspension was then cooled to room temperature. A permanent magnet was used to collect solids from the slurry. The collected solids were washed 5 times with water and dried at 60°C for 15 hours.

Example 6 Bead Encapsulation: Polymer Coating on Magnetic Core

[00133] 0.5 g of PMA (an alternating copolymer of polymethyl vinyl ether and maleic anhydride, molecular weight (MW) 260,000), 30 g of acetone and 2.0 g of a 100 nm core of magnetite were prepared according to example 2 and added to a 250 flask ml and stirred overnight. 30 g of dioxane was added to the flask. The suspension in the flask was heated to 80°C for 10 hours. The product was collected using a permanent magnet and washed with dioxane once and with methanol 3 times. The washed solid was transferred to a 250 ml flask and 85 g of water and 15 g of 1M acetic acid (in water) were added. The suspension in the flask was heated to 80°C for 3 hours. The solid product was collected and washed with water 5 times. The final solid product was dried in an oven at 60° C. overnight.

Example 7 Surface Functionalization: Magnetic Core Carboxylation

[00134] 2 g of 100 nm magnetite cores prepared according to Example 2 were mixed in a flask with 5 g of (3-triethoxysilyl) propyl succinic anhydride and 100 ml of toluene. The mixture was stirred to obtain a homogeneous suspension. The suspension was then heated at reflux for 24 h with stirring. After 24 h the heating was stopped and the suspension was cooled to room temperature. The product was then collected using a permanent magnet. The product was washed once with methanol and then washed with water 3 times. The product was transferred to a flask with 100 ml of 0.1 M acetic acid in water and stirred to obtain a homogeneous suspension. The suspension was then heated to 90°C for 15 h with stirring. After 15 h, heating was stopped and the suspension was allowed to cool to room temperature. The product was collected using a permanent magnet. The product was then washed with water 3 times. The product was then dried in an oven at 60° C. overnight.

Example 8. Obtaining magnetic beads with immobilized trypsin

[00135] 0.5 g of poly(acrylic acid) coated magnetic beads prepared according to example 5 were mixed in a flask with 20 ml of 0.1 M sodium phosphate buffer (pH 7.5) and 50 mg of tosylphenylalanyl chloromethyl ketone (TPCK) treated trypsin . The mixture was stirred to prepare a homogeneous suspension. 200 mg of 1-cyclohexyl-3-(2-morpholinoethyl)carbodiimide metho-p-toluenesulfonate was added to the suspension. The suspension was kept at 4°C for 24 h with stirring. The product was collected using a permanent magnet and washed with water 5 times. The product was then redispersed in 50 mM acetic acid in water and stored at 4°C.

Example 9 Nucleic Acid Isolation

[00136] The sample processing system according to the examples of this disclosure can be used to measure the concentration of DNA in the solution after elution. This method included two main parts: a preparation phase and a procedure implementation phase.

[00137] The preparation phase began with a binding buffer solution for SPRI (Surface Plasmon Resonance Imaging). The binding buffer solution for SPRI contained, for example, PEG (polyethylene glycol) and salt (NaCl). Carboxy-coated magnetic particles prepared according to Example 6 were then resuspended in SPRI binding buffer. The concentration of ferromagnetic particles was normalized to that of the standard AmpureXP binding buffer supplied as part of a product available under the trade designation AMPure XP ^TM available from Beckman Coulter, Bray, CA, USA.

[00138] After preparing the SPRI binding buffer, a fresh 80% ethanol solution was prepared. A DNA sample was then prepared by combining a 20 μm aliquot of a 100 bp DNA length marker, available under catalog number N3231S from New England BioLabs, INC., Ipswich, Massachusetts, USA, with 580 μl of DI water to obtain a 30:1 dilution . Then the power level of the control component was set to 100% and the frequency to 50 Hz of the sine wave. Plates and tubes were kept capped as far as possible to reduce change due to evaporation.

[00139] After the completion of the preparation phase, the implementation phase of the procedure began. In some examples, in parallel with the procedure described below, the same procedure was performed manually using standard AmpureXP binding buffer as a control. Some of the diluted DNA was kept as another control.

[00140] 50 µl of diluted DNA and 90 µl of a mixture of ferrimagnetic particles (e.g., SPRI binding buffer solution) were added to a 0.5 ml polymerase chain reaction (PCR) container (e.g., container) to selectively precipitate DNA in the sample. The sample handling system described herein was used to thoroughly mix the contents of the container to allow the precipitated DNA to bind to the magnetic particles.

[00141] After mixing the sample and the ferrimagnetic particles, the sample was incubated for 5 minutes while maintaining the ferrimagnetic particles in a suspended state. Then a magnet (for example, the electromagnets described herein) were used to isolate the ferrimagnetic particles from the solution until clear to allow removal of the supernatant.

[00142] 200 μl of 80% ethanol was added to the container. The sample handling system was then used to separate the ferrimagnetic particles and remove the supernatant.

[00143] 50 µl of deionized (DI) water was added to the container to elute the DNA from the magnetic particles. The sample handling system was used to thoroughly mix the sample. The sample was then incubated for 2 minutes while maintaining the ferrimagnetic particles in a suspended state. The magnet was then used to separate until clear and transfer the eluent solution to a new plate. After transferring the post-elution solution to a new plate, the DNA concentration in the post-elution solution was measured using, for example, a NanoDrop or PicoGreen assay. The concentration of the initially diluted DNA was then compared with the concentration after manual elution with AmpureXP.

[00144] The amount of isolated DNA is shown in FIG. 4A for the magnetic ball in the mixer. For comparison, in FIG. 4B shows the amount of DNA isolated with a magnetic bead using the appropriate procedure, but without mixing. As a further example, in FIG. 4C shows the amount of DNA that was isolated using the manual bead mixing procedure. The control bead was a paramagnetic bead designed as Comparative Bead 1 below. FIG. 4D shows baseline DNA levels in each example.

Example 10 Trypsin Cleavage

[00145] Magnetic beads were used for trypsin digestion according to the following procedure. The original phosphate buffered saline (PBS), available under the trade designation 10X PBS ^TM , available from Invitrogen, Carlsbad, CA, USA, was diluted 10 times. A 5 mg/ml solution of cytochrome C protein in PBS was prepared. 0.122 ml PBS, 0.125 ml 5 mg/ml cytochrome c protein solution were placed in a 1.5 ml vial. The magnetic beads with immobilized trypsin, obtained according to example 7, were washed with water 3 times. The water was removed to give a pellet with beads. 0.01 ml (granule volume) of trypsin-immobilized beads was added to a 1.5 ml vial. The vessel was placed on a magnetic stirrer and stirred for 20 minutes at 150 Hz and 80 mT to carry out trypsin digestion. Cleavage was stopped after stirring by adding 0.0278 ml of 1% formic acid. 0.1 ml of the solution was taken for analysis by HPLC. The results of HPLC analysis are shown in FIG. 5 showing the cleavage products. HPLC conditions were as follows.

Mobile phase: A - 0.1% TFA/FA in water; B - 0.1% TFA/FA in ACN.

Gradient: 0-0.5 min 1% B, 1-50% B for 30.5 min, 50% B for 5 min, 3 min. cleaning at 95% B, 5 min. re-eq. at 1% B.

Flow rate: 0.3 ml/min.

Temperature: 40°C.

UV detector: 214 nm.

Injection volume: 2 µl.

Example 11 Determination of characteristics in relation to the suitability of magnetic beads

[00146] Various magnetic beads were investigated for their ability to be 1) magnetic field sensitive enough to mix in water, 2) magnetic field sensitive enough to be able to mix in a solution of polyethylene glycol, sodium chloride, water, 3 ) their ability not to form lumps under magnetic forces, 4) their ability to be coated with carboxyl groups, 5) their ability to release nucleic acid, and 6) their ability to release nucleic acid in sufficient yield.

[00147] To assess the properties of 1-3, 5 μl of a solution of various beads was added to 140 μl of water or a solution of polyethylene glycol, sodium chloride, water and per well. To determine if they were magnetically sensitive enough to stir, the beads were lowered to the bottom of the well using a magnetic field and then mixed with an electromagnetic mixer. If the particles were completely dispersed to the surface of the liquid, the particles were determined to be sufficiently sensitive to stir, as shown in Table 2 with the inscription "yes", if they were not stirred in solution, the particles were determined to be magnetically insensitive enough to stir , which is indicated in table 2 with the inscription "no". If under electromagnetic stirring, the magnetic particles did not aggregate to form particle lumps, the particles were considered not to form lumps, which is shown in Table 2 with the inscription "yes", if lumps were present during stirring, the particles were considered to form lumps, which is shown in table 2 with the inscription "no". In order to determine whether the beads could be coated with carboxyl groups as in 4), the beads were subjected to the procedure essentially in accordance with Example 4, the beads which could be coated with carboxyl groups were thus indicated in Table 2 by the inscription "yes", the beads, which cannot be coated with carboxyl groups were thus indicated in Table 2 by the inscription "no".

[00148] To determine if the beads can be used for DNA extraction as in 5), 50 μl of a DNA sample was added to the well and mixed with the beads. Beads that provided DNA extraction were thus indicated in Table 2 with "yes", beads that did not provide DNA extraction were thus indicated in Table 2 with "no". To determine if beads can be used to isolate DNA to achieve a sufficient yield of 60% to 90% of the original DNA in 6), the yield was calculated and, if sufficient, reported in Table 2 with "yes", beads, which do not provide isolation of DNA to achieve sufficient yield, thus indicated in table 2 using the inscription "no".

[00149] Table 1 lists the various beads whose properties were studied above. The data shows that only the beads made in accordance with the present disclosure provided each required aspect of the present disclosure. Balls that differ in structure or magnetic properties have proven unsuitable for use in a mixer because the balls do not have any of properties 1-6 or combinations thereof. Beads tested as comparative examples include those obtained from General Electric, Chemicell, Bangs Laboratories, Pelitex, Spherotech, Creative Diagnostics, Lumigen, Perfinity, Ocean NanoTech, Cospheric, and BioChain. Of the large number examined, none provided the necessary aspects 1-6. To illustrate this point, a sample of these beads, designated in Table 1 and Table 2 as comparative beads, is compared to the magnetic bead of the present disclosure.

Table 1. Magnetic balls

Ball designation in table 2 Ball Description Comparison ball 1 SpeedBead ^TM available from General Electric, Boston, Massachusetts, USA Comparison ball 2 BioMagPlus COOH ^TM available from Bangs Laboratories, INC, Fishers, IN, USA Comparison Ball 3 ProMag 1 COOH ^TM available from Bangs Laboratories, INC, Fishers, IN, USA Comparison ball 4 4.4 µm fluorescent ferromagnetic bead available from Spherotech INC, Lake Forest, IL, USA Comparison ball 5 2.0 µm ferromagnetic bead available from Spherotech INC, Lake Forest, IL, USA Comparison ball 6 2 µm bead designated WHM-S001 ^TM available from Creative Diagnostics, New York, NY, USA Comparison ball 7 4 µm bead designated WHM-S002 ^TM available from Creative Diagnostics, New York, NY, USA Ball 1 Ball prepared according to example 7

Table 2. Properties of magnetic balls

Comparison ball 1 Comparison ball 2 Comparison Ball 3 Comparison ball 4 Comparison ball 5 Comparison ball 6 Comparison ball 7 Ball 1 Magnetic sensitive enough to stir (1) Not Not Not Not Not Yes Yes Yes Magnetic sensitive enough for good mixing in PEG+NaCl buffers, water, 80% ethanol (2) Not But But But Not Not Not Yes Non-clotting due to magnetic field (3) Yes But But But Yes Yes Yes Yes Capable of coating with carboxyl groups (4) Yes Yes Yes Not Yes Yes Yes Yes Capable of providing nucleic acid extraction (5) Yes Yes Yes Yes Yes But But Yes Capable of providing nucleic acid isolation in sufficient yield (6) Yes But Not Not Not But But Yes

The above descriptions are illustrative and not restrictive. Many variations of this disclosure will become apparent to those skilled in the art upon consideration of the disclosure. The scope of the present invention will thus be defined without reference to the above description, but should instead be defined with reference to the appended claims together with their full scope or equivalents.

[00150] One or more features from any example can be combined with one or more features from any other example without departing from the scope of this disclosure.

[00151] It is implied that the indication of the term in the singular means "one or more", unless specifically indicated otherwise.

[00152] All patents, patent applications, publications and descriptions mentioned above are incorporated herein by reference in their entirety.

Additional aspects

[00153] The following illustrative aspects are presented, the numbering of which should not be construed as indicating a level of importance.

[00154] In aspect 1, a sample processing system is provided, comprising:

a container configured to receive a sample for processing;

ferrimagnetic particles located in the container;

a magnetic assembly located along the periphery of the container for creating an alternating magnetic field in the container, thereby ensuring the movement of ferrimagnetic particles in the container; and

a control component connected to the magnetic assembly to control the alternating magnetic field.

[00155] In aspect 2, a sample processing system according to aspect 1 is provided, wherein the ferrimagnetic particles comprise a ferrite core.

[00156] In aspect 3, the sample processing system of aspect 2 is provided, wherein the ferrite core comprises soft magnetic ferrite.

[00157] In aspect 4, a sample processing system according to any one of aspects 2 or 3 is provided, wherein the ferrite core is selected from the group consisting of:

cobalt ferrite;

MnZn ferrite and

NiZn ferrite.

[00158] In aspect 5, a sample processing system according to any one of aspects 1-4 is provided, further comprising:

sample in a container.

[00159] In aspect 6, the sample processing system of aspect 5 is provided, wherein the ferrimagnetic particles further comprise a coating.

[00160] In aspect 7, the sample treatment system of aspect 6 is provided wherein the coating is a polymer or silica based layer to control the density of the ferrimagnetic particles to be close to that of the liquid.

[00161] In aspect 8, a sample processing system according to any one of aspects 6 or 7 is provided, wherein the coating comprises a capture reagent to capture the analyte in the sample.

[00162] In aspect 9, the sample processing system of aspect 8 is provided, wherein the capture reagent is an antibody.

[00163] In aspect 10, a sample treatment system according to any one of aspects 6-9 is provided, wherein the coating contains a functional group for adsorbing nucleic acids.

[00164] Aspect 11 provides the sample processing system of Aspect 10 wherein the functional group is a carboxyl group.

[00165] In aspect 12, a sample processing system according to any one of aspects 1-11 is provided, wherein the sample contains biomolecules.

[00166] In aspect 13, the sample processing system of aspect 12 is provided, wherein the biomolecules are nucleic acids or proteins.

[00167] In aspect 14, a sample processing system according to any one of aspects 1-13 is provided, further comprising:

a collection component capable of collecting the ferrimagnetic particles in the container, thereby separating the ferrimagnetic particles from the sample.

[00168] In aspect 15, a sample processing system according to any one of aspects 1-14 is provided, wherein the magnet assembly further comprises at least one magnetic structure, each magnetic structure comprising a plurality of electromagnets, each of the plurality of electromagnets comprising an electrically conductive coil disposed around a center line that runs in the direction of the central axis of the magnetic structure.

[00169] In aspect 16, a method for processing a sample is provided, the method comprising:

providing a container containing the ferrimagnetic particles and the sample; and

exposing the container to an alternating magnetic field, thereby causing ferrimagnetic particles to move within the container, and thereby processing the sample.

[00170] In aspect 17, the method of aspect 16 is provided, wherein the treatment comprises capturing the analyte in the sample.

[00171] In aspect 18, the method of aspect 17 is provided, wherein the ferrimagnetic particles comprise a capture reagent to capture the analyte in the sample.

[00172] In aspect 19, the method of aspect 18 is provided, wherein the capture reagent is an antibody.

[00173] In aspect 20, a method according to any one of aspects 17-19 is provided, wherein the ferrimagnetic particles contain a functional group for analyte adsorption.

[00174] In aspect 21, the method of aspect 20 is provided, wherein the analyte is a nucleic acid and the functional group is a carboxyl group.

[00175] In aspect 22, a method according to any one of aspects 16-21 is provided, further comprising:

collecting with the ferrimagnetic particle collecting component; and

eluting at least a portion of the sample from the container.

[00176] In aspect 23, a method according to any one of aspects 16-22 is provided, wherein the treatment comprises heating or stirring the sample by moving ferrimagnetic particles in a container.

[00177] In aspect 24, a method according to any one of aspects 16-23 is provided, wherein the ferrimagnetic particles comprise a ferrite core.

[00178] In aspect 25, the method of aspect 24 is provided, wherein the ferrite core comprises soft magnetic ferrite.

[00179] In aspect 26, the method of aspect 25 is provided, wherein the ferrite core is selected from the group consisting of:

cobalt ferrite;

MnZn ferrite and

NiZn ferrite.

[00180] In aspect 27, a method according to any one of aspects 16-26 is provided, wherein the ferrimagnetic particles further comprise a coating.

[00181] In aspect 28, the method of aspect 27 is provided, wherein the coating is a layer of a polymer layer or a silica-based layer to control that the density of the ferrimagnetic particles is close to that of the liquid.

[00182] In aspect 29, a method according to any one of aspects 16-28 is provided, wherein the sample contains biomolecules.

[00183] In aspect 30, the method of aspect 29 is provided, wherein the biomolecules are nucleic acids or proteins.

[00184] In aspect 31, a sample processing system is provided, comprising:

a container configured to receive a sample for processing;

magnetic particles disposed in a container, the magnetic particles having a maximum field strength ranging from about 20 emu/g to about 250 emu/g and a remanent magnetization ranging from about 0 emu/g to about 30 emu/g;

a magnetic assembly located on the periphery of the container for creating an alternating magnetic field in the container, thereby ensuring the movement of magnetic particles in the container; and

a control component connected to the magnetic assembly to control the alternating magnetic field.

[00185] In aspect 32, the sample processing system of aspect 31 is provided, wherein the magnetic particles comprise ferrimagnetic particles, ferromagnetic particles, paramagnetic particles, superparamagnetic particles, or a mixture thereof.

[00186] In aspect 32, the sample processing system of aspect 31 is provided, wherein the magnetic particles comprise ferrimagnetic particles.

[00187] In aspect 34, a sample processing system according to any one of aspects 31 or 33 is provided, wherein the maximum magnetic particle field strength is in the range of about 35 emu/g to about 100 emu/g.

[00188] In aspect 35, a sample processing system according to any one of aspects 31-34 is provided, wherein the remanence of the magnetic particles is in the range of about 0 emu/g to about 10 emu/g.

[00189] In aspect 36, a sample processing system according to any one of aspects 31-35 is provided, wherein the magnetic particles are porous and the individual pore size is in the range of about 5 U to about 1000 U.

[00190] In aspect 37, a sample processing system according to any one of aspects 31-36 is provided, wherein the magnetic particles are porous and the individual pore size is in the range of about 50 U to about 500 U.

[00191] In aspect 38, a sample processing system according to any one of aspects 31-37 is provided, wherein the magnetic particles comprise a ferrite core.

[00192] In aspect 39, a sample processing system according to any one of aspects 31-38 is provided, wherein the ferrite core comprises soft magnetic ferrite.

[00193] In aspect 40, a sample processing system according to any one of aspects 31-39 is provided, wherein the ferrite core is selected from the group consisting of Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS and FeOOH.

[00194] In aspect 41, a sample processing system according to any one of aspects 31-40 is provided, further comprising:

sample in a container.

[00195] In aspect 42, a sample processing system according to any one of aspects 31-41 is provided, wherein the magnetic particles further comprise a coating.

[00196] Aspect 43 provides the sample treatment system of aspect 42 wherein the coating comprises SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO _{2 ,} ceramic, polyacrylic acid, poly(methyl acrylate), polystyrene, divinylbenzene, polyvinylpyrrolidone , polyvinyl alcohol or a mixture thereof.

[00197] In aspect 44, a sample processing system according to any one of aspects 42 or 43 is provided, wherein the coating comprises a capture reagent to capture the analyte in the sample.

[00198] Aspect 45 provides the sample processing system of aspect 44 wherein the capture reagent contains a thiol group, streptavidin, an amino group, a hydroxyl group, a tosyl group, an epoxy group, an alkyl group, a vinyl group, an aryl group, an enzyme, a protein, a deoxyribonucleic acid, ribonucleic acid, immunoglobulin G, carboxyl group or monoclonal antibody.

[00199] In aspect 46, the sample treatment system of aspect 42 is provided, wherein the coating contains an enzyme and the sample contains an enzyme substrate.

[00200] In aspect 47, a sample processing system according to any one of aspects 31-46 is provided, wherein the sample contains biomolecules.

[00201] In aspect 48, the sample processing system of aspect 47 is provided, wherein the biomolecules are nucleic acids or proteins.

[00202] In aspect 49, a sample processing system according to any one of aspects 31-48 is provided, further comprising:

a collection component capable of collecting the magnetic particles in the container, thereby separating the magnetic particles from the sample.

[00203] In aspect 50, a sample processing system according to any one of aspects 31-49 is provided, wherein the magnet assembly further comprises at least one magnetic structure, each magnetic structure comprising a plurality of electromagnets, each of the plurality of electromagnets comprising an electrically conductive coil disposed around a central a line that runs in the direction of the central axis of the magnetic structure.

[00204] In aspect 51, a sample treatment system according to any one of aspects 31-50 is provided, wherein the permeability of the magnetic particle is sufficient to generate an induced magnetic field in the range of about 10 emu/g to about 250 emu/g when exposed to a magnetic field with a strength of range from about 700 oersted to about 800 oersteds.

[00205] In aspect 52, a sample processing system according to any one of aspects 31-51 is provided, wherein the permeability of the magnetic particle is sufficient to generate an induced magnetic field in the range of about 35 emu/g to about 100 emu/g when exposed to a magnetic field with a strength of range from about 700 oersted to about 800 oersteds.

[00206] In aspect 53, a method for processing a sample is provided, the method comprising:

providing a container containing magnetic particles and a sample in solution, wherein the magnetic particles have a ligand on the surface of the particles, wherein the ligand selectively interacts with an analyte of interest in the sample, the magnetic particles have a maximum field strength in the range of about 20 emu/g to about 250 emu/g g and remanence in the range from about 0 emu/g to about 30 emu/g;

incubating the solution so that the analyte of interest contacts the ligand on the surface of the magnetic particles, and

exposing the container to a magnetic field, thereby separating the magnetic particles from the sample.

[00207] Aspect 54 provides the method of Aspect 53, wherein the ligand is a capture reagent containing a thiol group, streptavidin, an amino group, a hydroxyl group, a tosyl group, an epoxy group, an alkyl group, a vinyl group, an aryl group, an enzyme, a protein, a deoxyribonucleic acid acid, ribonucleic acid, immunoglobulin G, carboxyl group, or monoclonal antibody.

[00208] Aspect 55 provides the method of any one of aspects 53 or 54, wherein the analyte is a nucleic acid and the functional group is a carboxyl group.

[00209] In aspect 56, a method according to any one of aspects 53-55 is provided, further comprising:

the implementation of the collection of magnetic particles using the component for collecting and

eluting at least a portion of the sample from the container.

[00210] In aspect 57, the method of any one of aspects 53-56 is provided, further comprising heating or stirring the sample by moving the magnetic particles in the container.

[00211] In aspect 58, a method according to any one of aspects 53-57 is provided, wherein the maximum field strength is in the range of about 35 emu/g to about 100 emu/g.

[00212] In aspect 59, the method of any one of aspects 53-58 is provided, wherein the remanence of the magnetic particles is in the range of about 0 emu/g to about 10 emu/g.

[00213] In aspect 60, a method according to any one of aspects 53-59 is provided, wherein the magnetic particles are porous and the individual pore size ranges from about 5 U to about 1000 U.

[00214] In aspect 61, a method according to any one of aspects 53-60 is provided, wherein the magnetic particles are porous and the individual pore size is in the range of about 50 U to about 500 U.

[00215] In aspect 62, a method according to any one of aspects 53-61 is provided, wherein the magnetic particles comprise a ferrite core.

[00216] In aspect 63, the method of aspect 62 is provided, wherein the ferrite core comprises soft magnetic ferrite.

[00217] In aspect 64, a method according to any one of aspects 61-63 is provided, wherein the ferrite core is selected from the group consisting of Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS and FeOOH.

[00218] In aspect 65, a method according to any one of aspects 53-64 is provided, wherein the magnetic particles further comprise a coating.

[00219] Aspect 66 provides the method of aspect 65 wherein the coating comprises SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO _{2 ,} ceramic, polyacrylic acid, poly(methyl acrylate), polystyrene, divinylbenzene, polyvinylpyrrolidone, polyvinyl alcohol or a mixture thereof.

[00220] In aspect 67, the method of any one of aspects 53-66 is provided, wherein the analyte of interest comprises biomolecules.

[00221] In aspect 68, the method of aspect 67 is provided, wherein the biomolecules are nucleic acids or proteins.

[00222] Aspect 69 provides the method of any one of aspects 53-68, wherein the ligand is an enzyme and the analyte of interest is a substrate of the enzyme.

[00223] In aspect 70, the method of aspect 69 is provided, wherein the enzyme degrades the substrate.

[00224] In aspect 71, the method of any one of aspects 53-70 is provided, wherein the magnetic particle comprises ferrimagnetic particles, ferromagnetic particles, paramagnetic particles, superparamagnetic particles, or a mixture thereof.

[00225] Aspect 72 provides the method of any one of aspects 53-71, wherein the magnetic particle has a permeability sufficient to generate an induced magnetic field in the range of about 10 emu/g to about 250 emu/g when exposed to a magnetic field strength in the range of about 700 oersted to about 800 oersteds.

[00226] Aspect 73 provides a method according to any one of aspects 53-72, wherein the permeability of the magnetic particle is sufficient to generate an induced magnetic field in the range of about 35 emu/g to about 100 emu/g when exposed to a magnetic field strength in the range of about 700 oersted to about 800 oersteds.

[00227] In aspect 74, a magnetic particle is provided for processing a sample solution, the magnetic particle comprising:

a magnetic material having a maximum field strength in the range of about 20 emu/g to about 250 emu/g and a remanence in the range of about 0 emu/g to about 10 emu/g; and

the outer surface containing the ligand, while the ligand interacts with the analyte of interest in the sample solution.

[00228] Aspect 75 provides the magnetic particle of aspect 74 wherein the maximum field strength is in the range of about 35 emu/g to about 100 emu/g.

[00229] In aspect 76, a magnetic particle according to any one of aspects 74 or 75 is provided, wherein the remanence of the magnetic particle is in the range of about 0 emu/g to about 10 emu/g.

[00230] In aspect 77, a magnetic particle according to any one of aspects 74-76 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 5 E to about 1000 E.

[00231] In aspect 78, a magnetic particle according to any one of aspects 74-77 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 50 U to about 500 U.

[00232] In aspect 79, a magnetic particle according to any one of aspects 74-78 is provided, wherein the magnetic material comprises soft magnetic ferrite.

[00233] In aspect 80, a magnetic particle according to any one of aspects 74-79 is provided, wherein the magnetic material is selected from the group consisting of Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS and FeOOH.

[00234] Aspect 81 provides a magnetic particle according to any one of aspects 74-80, wherein the outer surface comprises SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO _{2 ,} ceramic, polyacrylic acid, poly(methyl acrylate), polystyrene , divinylbenzene, polyvinylpyrrolidone, polyvinyl alcohol, or a mixture thereof.

[00235] Aspect 82 provides a magnetic particle according to any one of aspects 74-81, wherein the ligand is a capture reagent containing a thiol group, streptavidin, an amino group, a hydroxyl group, a tosyl group, an epoxy group, an alkyl group, a vinyl group, an aryl group, enzyme, protein, deoxyribonucleic acid, ribonucleic acid, immunoglobulin G, carboxyl group, or monoclonal antibody.

[00236] Aspect 83 provides the magnetic particle of any one of aspects 74-82, wherein the ligand is an enzyme and the analyte of interest is a substrate of the enzyme.

[00237] Aspect 84 provides the magnetic particle of aspect 83 wherein the enzyme degrades the substrate.

[00238] In aspect 85, a magnetic particle according to any one of aspects 74-84 is provided, wherein the magnetic material comprises a ferrimagnetic material, a ferromagnetic material, a paramagnetic material, a superparamagnetic material, or a mixture thereof.

[00239] In aspect 86, a magnetic particle according to any one of aspects 74-85 is provided, wherein the magnetic particle has a permeability sufficient to generate an induced magnetic field in the range of about 10 emu/g to about 250 emu/g when exposed to a magnetic field with a strength in the range from about 700 oersted to about 800 oersted.

[00240] In aspect 87, a magnetic particle according to any one of aspects 74-86 is provided, wherein the magnetic particle has a permeability sufficient to generate an induced magnetic field in the range of about 35 emu/g to about 100 emu/g when exposed to a magnetic field with a strength in the range from about 700 oersted to about 800 oersted.

[00241] In aspect 88, a magnetic particle is provided for processing a sample solution, the magnetic particle comprising:

a core or inner layer containing magnetic material; and

an outer surface layer containing a capture reagent that selectively binds to the analyte of interest in the sample solution,

wherein the magnetic particle has a maximum field strength in the range of about 20 emu/g to about 250 emu/g and a remanence in the range of about 0 emu/g to about 10 emu/g.

[00242] In aspect 89, the magnetic particle of aspect 88 is provided, wherein the maximum field strength of the magnetic particle is in the range of about 35 emu/g to about 100 emu/g.

[00243] In aspect 90, a magnetic particle according to any one of aspects 88 or 89 is provided, wherein the remanence is in the range of about 0 emu/g to about 10 emu/g.

[00244] In aspect 91, a magnetic particle according to any one of aspects 88-90 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 5 E to about 1000 E.

[00245] In aspect 92, a magnetic particle according to any one of aspects 88-91 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 50 U to about 500 U.

[00246] In aspect 93, a magnetic particle according to any one of aspects 88-92 is provided, wherein the core or inner layer comprises soft magnetic ferrite.

[00247] In aspect 94, a magnetic particle according to any one of aspects 88-93 is provided, wherein the core or inner layer comprises a material selected from the group consisting of Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS and FeOOH.

[00248] In aspect 95, a magnetic particle according to any one of aspects 88-94 is provided, wherein the outer surface layer comprises SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO _{2 ,} ceramic, polyacrylic acid, poly(methyl acrylate), polystyrene, divinylbenzene, polyvinylpyrrolidone, polyvinyl alcohol, or a mixture thereof.

[00249] Aspect 96 provides a magnetic particle according to any one of aspects 88-95, wherein the outer surface layer further comprises a capture reagent containing a thiol group, streptavidin, an amino group, a hydroxyl group, a tosyl group, an epoxy group, an alkyl group, a vinyl group, an aryl group, enzyme, protein, deoxyribonucleic acid, ribonucleic acid, immunoglobulin G, carboxyl group, or monoclonal antibody.

[00250] In aspect 97, a magnetic particle according to any one of aspects 88-96 is provided, wherein the magnetic particle comprises ferrimagnetic materials, ferromagnetic materials, paramagnetic materials, superparamagnetic materials, or a mixture thereof.

[00251] In aspect 98, a magnetic particle according to any one of aspects 88-97 is provided, wherein the magnetic particle has a permeability sufficient to generate an induced magnetic field in the range of about 10 emu/g to about 250 emu/g when exposed to a magnetic field with a strength in the range from about 700 oersted to about 800 oersted.

[00252] In aspect 99, a magnetic particle according to any one of aspects 88-98 is provided, wherein the magnetic particle has a permeability sufficient to generate an induced magnetic field in the range of about 35 emu/g to about 100 emu/g when exposed to a magnetic field with a strength in the range from about 700 oersted to about 800 oersted.

[00253] In aspect 100, a method for processing a sample is provided, the method comprising:

providing a magnetic particle having a ligand on the surface of the particle, wherein the ligand interacts selectively with an analyte of interest in the sample, the magnetic particle has a maximum field strength in the range of about 20 emu/g to about 250 emu/g and a remanence in the range of about 0 emu/g to about 10 emu/g; and

bringing the solution containing the analyte of interest into contact with the magnetic particle to cause the ligand to interact with the analyte of interest.

[00254] In aspect 101, the method of aspect 100 is provided, further comprising exposing the magnetic particle to a magnetic field, thereby causing the magnetic particle to be separated from the solution.

[00255] In aspect 102, the method of any one of aspects 100 or 101 is provided, wherein the ligand is a capture reagent.

[00256] Aspect 103 provides the method of aspect 102, wherein the capture reagent is a thiol group, streptavidin, amino group, hydroxyl group, tosyl group, epoxy group, alkyl group, vinyl group, aryl group, enzyme, protein, deoxyribonucleic acid, ribonucleic acid, immunoglobulin G, or monoclonal antibody.

[00257] Aspect 104 provides the method of any one of aspects 100-103, wherein the analyte is a nucleic acid and the functional group is a carboxyl group.

[00258] Aspect 105 provides the method of any one of aspects 100-104, wherein the ligand is an enzyme and the analyte of interest is a substrate of the enzyme.

[00259] Aspect 106 provides the method of aspect 105 wherein the enzyme degrades the substrate.

[00260] In aspect 107, a method according to any one of aspects 100-106 is provided, further comprising:

the implementation of the collection of the magnetic particle using the component for collecting and

eluting at least a portion of the sample.

[00261] In aspect 108, the method of any one of aspects 100-107 is provided, further comprising heating or stirring the sample by moving the magnetic particle.

[00262] In aspect 109, the method of any one of aspects 100-108 is provided, wherein the maximum magnetic particle field strength is in the range of about 35 emu/g to about 100 emu/g.

[00263] In aspect 110, a method according to any one of aspects 100-109 is provided, wherein the remanence of the magnetic particle is in the range of about 0 emu/g to about 10 emu/g.

[00264] In aspect 111, a method according to any one of aspects 100-110 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 5 U to about 1000 U.

[00265] In aspect 112, the method of any one of aspects 100-111 is provided, wherein the magnetic particle is porous and the individual pore size is in the range of about 50 U to about 500 U.

[00266] In aspect 113, the method of any one of aspects 100-112 is provided, wherein the magnetic particle comprises a ferrimagnetic core, a ferromagnetic core, a paramagnetic core, or a superparamagnetic core.

[00267] In aspect 114, the method of any one of aspects 100-113 is provided, wherein the magnetic particle comprises a ferrite core.

[00268] In aspect 115, the method of aspect 114 is provided, wherein the ferrite core comprises soft magnetic ferrite.

[00269] In aspect 116, the method of any one of aspects 114-115 is provided, wherein the ferrite core is selected from the group consisting of Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS and FeOOH.

[00270] In aspect 117, a method according to any one of aspects 100-116 is provided, wherein the magnetic particle further comprises a coating.

[00271] Aspect 118 provides the method of aspect 117 wherein the coating comprises SiO ₂ , TiO ₂ , ZnO ₂ , Al ₂ O ₃ , CeO _{2 ,} ceramic, polyacrylic acid, poly(methyl acrylate), polystyrene, divinylbenzene, polyvinylpyrrolidone, polyvinyl alcohol or a mixture thereof.

[00272] In aspect 119, the method of any one of aspects 100-118 is provided, wherein the analyte of interest comprises biomolecules.

[00273] In aspect 120, the method of aspect 119 is provided, wherein the biomolecules are nucleic acids or proteins.

[00274] In aspect 121, the method of any one of aspects 100-120 is provided, wherein the permeability of the magnetic particle is sufficient to generate an induced magnetic field in the range of about 10 emu/g to about 250 emu/g when exposed to a magnetic field strength in the range of about 700 oersted to about 800 oersteds.

[00275] In aspect 122, a method according to any one of aspects 100-121 is provided, wherein the permeability of the magnetic particle is sufficient to generate an induced magnetic field in the range of about 35 emu/g to about 100 emu/g when exposed to a magnetic field strength in the range of about 700 oersted to about 800 oersteds.

Claims (22)

1. A magnetic particle for processing a sample solution, comprising: a magnetic material having a maximum field strength in the range of 20 emu/g to 250 emu/g and a remanence in the range of 0 emu/g to 30 emu/g; and a ligand attached to the outer surface of a magnetic particle, the ligand interacting with the analyte of interest in the sample solution, wherein the magnetic particle has a diameter of at least 100 nm. 2. The magnetic particle of claim 1, wherein the magnetic material comprises a ferrimagnetic material. 3. Magnetic particle according to claim 1 or 2, in which the magnetic material contains Fe ₃ O ₄ , Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS or FeOOH. 4. Magnetic particle according to any one of paragraphs. 1-3, in which the ligand contains a thiol group, streptavidin, amino group, hydroxyl group, tosyl group, epoxy group, alkyl group, vinyl group, aryl group, enzyme, protein, deoxyribonucleic acid, ribonucleic acid, immunoglobulin G, carboxyl group, or monoclonal antibody . 5. Magnetic particle according to any one of paragraphs. 1-4, in which the ligand contains a carboxyl group. 6. Magnetic particle according to any one of paragraphs. 1-5, in which the maximum field strength is in the range from 35 emu/g to 100 emu/g. 7. Magnetic particle according to any one of paragraphs. 1-6, in which the remanence is in the range of 0 emu/g to 10 emu/g. 8. Sample processing method, including: providing a magnetic particle having a ligand attached to the outer surface of the particle, wherein the ligand interacts with the analyte of interest in the sample, wherein the magnetic particle has a maximum field strength in the range of 20 emu/g to 250 emu/g, a remanent magnetization in the range of 0 emu/g to 30 emu/g and a diameter of at least 100 nm; and bringing the solution containing the analyte of interest into contact with the magnetic particle to cause the ligand to interact with the analyte of interest. 9. The method of claim 8, further comprising exposing the magnetic particle to a magnetic field, thereby causing the magnetic particle to be separated from the solution. 10. The method of claim 8 or 9, wherein the analyte of interest is a nucleic acid. 11. The method according to any one of paragraphs. 8-10, while the maximum field strength is in the range from 35 emu/g to 100 emu/g. 12. The method according to any one of paragraphs. 8-11, while the remanence is in the range from 0 emu/g to 10 emu/g. 13. The method according to any one of paragraphs. 8-12, wherein the magnetic particle contains a ferrimagnetic material. 14. The method according to any one of paragraphs. 8-13, while the magnetic particle contains Fe ₃ O ₄ , Fe ₂ TiO ₂ , FeTiO ₂ , MnFe ₂ O ₄ , NiFe ₂ O ₄ , MgFe ₂ O ₄ , Fe ₇ S ₈ , Fe ₃ S ₄ , FeS or FeOOH . 15. The method according to any one of paragraphs. 8-14, wherein the ligand contains a thiol group, streptavidin, an amino group, a hydroxyl group, a tosyl group, an epoxy group, an alkyl group, a vinyl group, an aryl group, an enzyme, a protein, a deoxyribonucleic acid, a ribonucleic acid, an immunoglobulin G, a carboxyl group, or a monoclonal antibody . 16. The magnetic particle according to claim 1, further comprising a coating layer enclosing the magnetic particle. 17. The magnetic particle of claim 16 wherein the coating layer contains silica.

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